diff --git a/01-run-quit.html b/01-run-quit.html
index d273a5c60..06bc564b0 100644
--- a/01-run-quit.html
+++ b/01-run-quit.html
@@ -718,7 +718,7 @@ <h4 class="accordion-header" id="headingSolution1">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
 <div class="accordion-body">
 <p>After creating the necessary tabs, you can drag one of the tabs to
 the center of a panel to move the tab to the panel; next you can
@@ -785,7 +785,7 @@ <h4 class="accordion-header" id="headingSolution2">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
 <div class="accordion-body">
 <p>Command mode has a grey border and Edit mode has a blue border. Use
 <kbd>Esc</kbd> and <kbd>Return</kbd> to switch between modes. You need
@@ -949,7 +949,7 @@ <h4 class="accordion-header" id="headingSolution3">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
 <div class="accordion-body">
 <p>This challenge integrates both the numbered list and bullet list.
 Note that the bullet list is indented 2 spaces so that it is inline with
@@ -992,7 +992,7 @@ <h4 class="accordion-header" id="headingSolution4">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution4" class="accordion-collapse collapse" aria-labelledby="headingSolution4" data-bs-parent="#accordionSolution4">
+<div id="collapseSolution4" class="accordion-collapse collapse" data-bs-parent="#accordionSolution4" aria-labelledby="headingSolution4">
 <div class="accordion-body">
 <p>Python returns the output of the last calculation.</p>
 <div class="codewrapper sourceCode" id="cb12">
@@ -1037,7 +1037,7 @@ <h4 class="accordion-header" id="headingSolution5">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution5" class="accordion-collapse collapse" aria-labelledby="headingSolution5" data-bs-parent="#accordionSolution5">
+<div id="collapseSolution5" class="accordion-collapse collapse" data-bs-parent="#accordionSolution5" aria-labelledby="headingSolution5">
 <div class="accordion-body">
 <p>The Python code gets treated like Markdown text. The lines appear as
 if they are part of one contiguous paragraph. This could be useful to
@@ -1077,7 +1077,7 @@ <h4 class="accordion-header" id="headingSolution6">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution6" class="accordion-collapse collapse" aria-labelledby="headingSolution6" data-bs-parent="#accordionSolution6">
+<div id="collapseSolution6" class="accordion-collapse collapse" data-bs-parent="#accordionSolution6" aria-labelledby="headingSolution6">
 <div class="accordion-body">
 <p>The notebook shows the equation as it would be rendered from LaTeX
 equation syntax. The dollar sign, <code>$</code>, is used to tell
@@ -1188,7 +1188,7 @@ <h3 class="callout-title">Keypoints<a class="anchor" aria-label="anchor" href="#
   "identifier": "https://swcarpentry.github.io/python-novice-gapminder/01-run-quit.html",
   "dateCreated": "2016-01-07",
   "dateModified": "2023-06-07",
-  "datePublished": "2023-07-18"
+  "datePublished": "2023-07-24"
 }
 
   </script><script>
diff --git a/02-variables.html b/02-variables.html
index 57b791062..1c819fd96 100644
--- a/02-variables.html
+++ b/02-variables.html
@@ -672,7 +672,7 @@ <h4 class="accordion-header" id="headingSolution1">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
 <div class="accordion-body">
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -719,7 +719,7 @@ <h4 class="accordion-header" id="headingSolution2">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
 <div class="accordion-body">
 <div class="codewrapper sourceCode" id="cb20">
 <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -761,7 +761,7 @@ <h4 class="accordion-header" id="headingSolution3">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
 <div class="accordion-body">
 <p>Numbers are not strings or sequences and Python will raise an error
 if you try to perform an index operation on a number. In the <a href="03-types-conversion.html">next lesson on types and type
@@ -819,7 +819,7 @@ <h4 class="accordion-header" id="headingSolution4">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution4" class="accordion-collapse collapse" data-bs-parent="#accordionSolution4" aria-labelledby="headingSolution4">
+<div id="collapseSolution4" class="accordion-collapse collapse" aria-labelledby="headingSolution4" data-bs-parent="#accordionSolution4">
 <div class="accordion-body">
 <p><code>minutes</code> is better because <code>min</code> might mean
 something like “minimum” (and actually is an existing built-in function
@@ -853,7 +853,7 @@ <h4 class="accordion-header" id="headingSolution5">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution5" class="accordion-collapse collapse" data-bs-parent="#accordionSolution5" aria-labelledby="headingSolution5">
+<div id="collapseSolution5" class="accordion-collapse collapse" aria-labelledby="headingSolution5" data-bs-parent="#accordionSolution5">
 <div class="accordion-body">
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -903,7 +903,7 @@ <h4 class="accordion-header" id="headingSolution6">
   Solutions
   </h4>
 </button>
-<div id="collapseSolution6" class="accordion-collapse collapse" data-bs-parent="#accordionSolution6" aria-labelledby="headingSolution6">
+<div id="collapseSolution6" class="accordion-collapse collapse" aria-labelledby="headingSolution6" data-bs-parent="#accordionSolution6">
 <div class="accordion-body">
 <ol style="list-style-type: decimal"><li>
 <code>species_name[2:8]</code> returns the substring
@@ -1012,7 +1012,7 @@ <h3 class="callout-title">Keypoints<a class="anchor" aria-label="anchor" href="#
   "identifier": "https://swcarpentry.github.io/python-novice-gapminder/02-variables.html",
   "dateCreated": "2016-01-07",
   "dateModified": "2023-05-02",
-  "datePublished": "2023-07-18"
+  "datePublished": "2023-07-24"
 }
 
   </script><script>
diff --git a/03-types-conversion.html b/03-types-conversion.html
index 280fa0ee0..3469dc805 100644
--- a/03-types-conversion.html
+++ b/03-types-conversion.html
@@ -1092,7 +1092,7 @@ <h3 class="callout-title">Keypoints<a class="anchor" aria-label="anchor" href="#
   "identifier": "https://swcarpentry.github.io/python-novice-gapminder/03-types-conversion.html",
   "dateCreated": "2016-01-07",
   "dateModified": "2023-05-02",
-  "datePublished": "2023-07-18"
+  "datePublished": "2023-07-24"
 }
 
   </script><script>
diff --git a/04-built-in.html b/04-built-in.html
index 433fa37c1..80a6ee24d 100644
--- a/04-built-in.html
+++ b/04-built-in.html
@@ -736,7 +736,7 @@ <h4 class="accordion-header" id="headingSolution1">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
 <div class="accordion-body">
 <ol style="list-style-type: decimal"><li>Order of operations:</li>
 <li><code>1.1 * radiance = 1.1</code></li>
@@ -782,7 +782,7 @@ <h4 class="accordion-header" id="headingSolution2">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
 <div class="accordion-body">
 <div class="codewrapper sourceCode" id="cb30">
 <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -850,7 +850,7 @@ <h4 class="accordion-header" id="headingSolution3">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
 <div class="accordion-body">
 <p><code>max</code> and <code>min</code> return TypeErrors in this case
 because the correct number of parameters was not supplied. If it just
@@ -883,7 +883,7 @@ <h4 class="accordion-header" id="headingSolution4">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution4" class="accordion-collapse collapse" aria-labelledby="headingSolution4" data-bs-parent="#accordionSolution4">
+<div id="collapseSolution4" class="accordion-collapse collapse" data-bs-parent="#accordionSolution4" aria-labelledby="headingSolution4">
 <div class="accordion-body">
 <p><code>name[len(name) - 1]</code></p>
 </div>
@@ -991,7 +991,7 @@ <h3 class="callout-title">Keypoints<a class="anchor" aria-label="anchor" href="#
   "identifier": "https://swcarpentry.github.io/python-novice-gapminder/04-built-in.html",
   "dateCreated": "2016-01-07",
   "dateModified": "2023-05-02",
-  "datePublished": "2023-07-18"
+  "datePublished": "2023-07-24"
 }
 
   </script><script>
diff --git a/05-coffee.html b/05-coffee.html
index f9b8fc3a1..000494452 100644
--- a/05-coffee.html
+++ b/05-coffee.html
@@ -449,7 +449,7 @@ <h1>Morning Coffee</h1>
   "identifier": "https://swcarpentry.github.io/python-novice-gapminder/05-coffee.html",
   "dateCreated": "2016-01-07",
   "dateModified": "2023-05-02",
-  "datePublished": "2023-07-18"
+  "datePublished": "2023-07-24"
 }
 
   </script><script>
diff --git a/06-libraries.html b/06-libraries.html
index 0a8dafea2..b6d9e8a2e 100644
--- a/06-libraries.html
+++ b/06-libraries.html
@@ -583,7 +583,7 @@ <h4 class="accordion-header" id="headingSolution1">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
 <div class="accordion-body">
 <ol style="list-style-type: decimal"><li><p>Using <code>help(math)</code> we see that we’ve got
 <code>pow(x,y)</code> in addition to <code>sqrt(x)</code>, so we could
@@ -629,7 +629,7 @@ <h4 class="accordion-header" id="headingSolution2">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
 <div class="accordion-body">
 <p>The <a href="https://docs.python.org/3/library/random.html" class="external-link">random
 module</a> seems like it could help.</p>
@@ -711,7 +711,7 @@ <h4 class="accordion-header" id="headingSolution3">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
 <div class="accordion-body">
 <div class="codewrapper sourceCode" id="cb15">
 <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -753,7 +753,7 @@ <h4 class="accordion-header" id="headingSolution4">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution4" class="accordion-collapse collapse" aria-labelledby="headingSolution4" data-bs-parent="#accordionSolution4">
+<div id="collapseSolution4" class="accordion-collapse collapse" data-bs-parent="#accordionSolution4" aria-labelledby="headingSolution4">
 <div class="accordion-body">
 <p>Importing the math module (<code>import math</code>)</p>
 </div>
@@ -790,7 +790,7 @@ <h4 class="accordion-header" id="headingSolution5">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution5" class="accordion-collapse collapse" aria-labelledby="headingSolution5" data-bs-parent="#accordionSolution5">
+<div id="collapseSolution5" class="accordion-collapse collapse" data-bs-parent="#accordionSolution5" aria-labelledby="headingSolution5">
 <div class="accordion-body">
 <div class="codewrapper sourceCode" id="cb18">
 <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -846,7 +846,7 @@ <h4 class="accordion-header" id="headingSolution6">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution6" class="accordion-collapse collapse" aria-labelledby="headingSolution6" data-bs-parent="#accordionSolution6">
+<div id="collapseSolution6" class="accordion-collapse collapse" data-bs-parent="#accordionSolution6" aria-labelledby="headingSolution6">
 <div class="accordion-body">
 <ol style="list-style-type: decimal"><li>Library calls 1 and 4. In order to directly refer to
 <code>sin</code> and <code>pi</code> without the library name as prefix,
@@ -904,7 +904,7 @@ <h4 class="accordion-header" id="headingSolution7">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution7" class="accordion-collapse collapse" aria-labelledby="headingSolution7" data-bs-parent="#accordionSolution7">
+<div id="collapseSolution7" class="accordion-collapse collapse" data-bs-parent="#accordionSolution7" aria-labelledby="headingSolution7">
 <div class="accordion-body">
 <div class="codewrapper sourceCode" id="cb21">
 <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -951,7 +951,7 @@ <h4 class="accordion-header" id="headingSolution8">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution8" class="accordion-collapse collapse" aria-labelledby="headingSolution8" data-bs-parent="#accordionSolution8">
+<div id="collapseSolution8" class="accordion-collapse collapse" data-bs-parent="#accordionSolution8" aria-labelledby="headingSolution8">
 <div class="accordion-body">
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1046,7 +1046,7 @@ <h3 class="callout-title">Keypoints<a class="anchor" aria-label="anchor" href="#
   "identifier": "https://swcarpentry.github.io/python-novice-gapminder/06-libraries.html",
   "dateCreated": "2016-01-07",
   "dateModified": "2023-05-02",
-  "datePublished": "2023-07-18"
+  "datePublished": "2023-07-24"
 }
 
   </script><script>
diff --git a/07-reading-tabular.html b/07-reading-tabular.html
index 14fedf528..a48e4c9e9 100644
--- a/07-reading-tabular.html
+++ b/07-reading-tabular.html
@@ -1005,7 +1005,7 @@ <h3 class="callout-title">Keypoints<a class="anchor" aria-label="anchor" href="#
   "identifier": "https://swcarpentry.github.io/python-novice-gapminder/07-reading-tabular.html",
   "dateCreated": "2016-01-07",
   "dateModified": "2023-05-02",
-  "datePublished": "2023-07-18"
+  "datePublished": "2023-07-24"
 }
 
   </script><script>
diff --git a/08-data-frames.html b/08-data-frames.html
index ec79fd5ef..938b63385 100644
--- a/08-data-frames.html
+++ b/08-data-frames.html
@@ -388,7 +388,7 @@ <h2 class="accordion-header" id="flush-headingTwelve">
       </div>
       <hr></nav><main id="main-content" class="main-content"><div class="container lesson-content">
         <h1>Pandas DataFrames</h1>
-        <p> Last updated on 2023-06-05 | 
+        <p> Last updated on 2023-07-24 | 
         
         <a href="https://github.com/swcarpentry/python-novice-gapminder/edit/main/episodes/08-data-frames.md" class="external-link">Edit this page <i aria-hidden="true" data-feather="edit"></i></a></p>
         
@@ -761,7 +761,7 @@ <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"><
 </h3>
 <pre class="sourceCode python" tabindex="0"><code class="sourceCode python"><span id="cb25-1"><a href="#cb25-1" aria-hidden="true" tabindex="-1"></a><span class="im">import</span> pandas <span class="im">as</span> pd</span>
 <span id="cb25-2"><a href="#cb25-2" aria-hidden="true" tabindex="-1"></a></span>
-<span id="cb25-3"><a href="#cb25-3" aria-hidden="true" tabindex="-1"></a>df <span class="op">=</span> pd.read_csv(<span class="st">'data/gapminder_gdp_europe.csv'</span>, index_col<span class="op">=</span><span class="st">'country'</span>)</span></code></pre>
+<span id="cb25-3"><a href="#cb25-3" aria-hidden="true" tabindex="-1"></a>data_europe <span class="op">=</span> pd.read_csv(<span class="st">'data/gapminder_gdp_europe.csv'</span>, index_col<span class="op">=</span><span class="st">'country'</span>)</span></code></pre>
 </div>
 <p>Write an expression to find the Per Capita GDP of Serbia in 2007.</p>
 </div>
@@ -774,14 +774,14 @@ <h4 class="accordion-header" id="headingSolution1">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
 <div class="accordion-body">
 <p>The selection can be done by using the labels for both the row
 (“Serbia”) and the column (“gdpPercap_2007”):</p>
 <div class="codewrapper sourceCode" id="cb26">
 <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode python" tabindex="0"><code class="sourceCode python"><span id="cb26-1"><a href="#cb26-1" aria-hidden="true" tabindex="-1"></a><span class="bu">print</span>(df.loc[<span class="st">'Serbia'</span>, <span class="st">'gdpPercap_2007'</span>])</span></code></pre>
+<pre class="sourceCode python" tabindex="0"><code class="sourceCode python"><span id="cb26-1"><a href="#cb26-1" aria-hidden="true" tabindex="-1"></a><span class="bu">print</span>(data_europe.loc[<span class="st">'Serbia'</span>, <span class="st">'gdpPercap_2007'</span>])</span></code></pre>
 </div>
 <p>The output is</p>
 <div class="codewrapper">
@@ -807,8 +807,8 @@ <h3 class="callout-title">Extent of Slicing<a class="anchor" aria-label="anchor"
 </ol><div class="codewrapper sourceCode" id="cb28">
 <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode python" tabindex="0"><code class="sourceCode python"><span id="cb28-1"><a href="#cb28-1" aria-hidden="true" tabindex="-1"></a><span class="bu">print</span>(df.iloc[<span class="dv">0</span>:<span class="dv">2</span>, <span class="dv">0</span>:<span class="dv">2</span>])</span>
-<span id="cb28-2"><a href="#cb28-2" aria-hidden="true" tabindex="-1"></a><span class="bu">print</span>(df.loc[<span class="st">'Albania'</span>:<span class="st">'Belgium'</span>, <span class="st">'gdpPercap_1952'</span>:<span class="st">'gdpPercap_1962'</span>])</span></code></pre>
+<pre class="sourceCode python" tabindex="0"><code class="sourceCode python"><span id="cb28-1"><a href="#cb28-1" aria-hidden="true" tabindex="-1"></a><span class="bu">print</span>(data_europe.iloc[<span class="dv">0</span>:<span class="dv">2</span>, <span class="dv">0</span>:<span class="dv">2</span>])</span>
+<span id="cb28-2"><a href="#cb28-2" aria-hidden="true" tabindex="-1"></a><span class="bu">print</span>(data_europe.loc[<span class="st">'Albania'</span>:<span class="st">'Belgium'</span>, <span class="st">'gdpPercap_1952'</span>:<span class="st">'gdpPercap_1962'</span>])</span></code></pre>
 </div>
 </div>
 </div>
@@ -820,7 +820,7 @@ <h4 class="accordion-header" id="headingSolution2">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
 <div class="accordion-body">
 <p>No, they do not produce the same output! The output of the first
 statement is:</p>
@@ -881,7 +881,7 @@ <h4 class="accordion-header" id="headingSolution3">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
 <div class="accordion-body">
 <p>Let’s go through this piece of code line by line.</p>
 <div class="codewrapper sourceCode" id="cb32">
@@ -965,7 +965,7 @@ <h4 class="accordion-header" id="headingSolution4">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution4" class="accordion-collapse collapse" data-bs-parent="#accordionSolution4" aria-labelledby="headingSolution4">
+<div id="collapseSolution4" class="accordion-collapse collapse" aria-labelledby="headingSolution4" data-bs-parent="#accordionSolution4">
 <div class="accordion-body">
 <p>For each column in <code>data</code>, <code>idxmin</code> will return
 the index value corresponding to each column’s minimum;
@@ -1003,7 +1003,7 @@ <h4 class="accordion-header" id="headingSolution5">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution5" class="accordion-collapse collapse" data-bs-parent="#accordionSolution5" aria-labelledby="headingSolution5">
+<div id="collapseSolution5" class="accordion-collapse collapse" aria-labelledby="headingSolution5" data-bs-parent="#accordionSolution5">
 <div class="accordion-body">
 <p>1:</p>
 <div class="codewrapper sourceCode" id="cb38">
@@ -1080,7 +1080,7 @@ <h4 class="accordion-header" id="headingSolution6">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution6" class="accordion-collapse collapse" data-bs-parent="#accordionSolution6" aria-labelledby="headingSolution6">
+<div id="collapseSolution6" class="accordion-collapse collapse" aria-labelledby="headingSolution6" data-bs-parent="#accordionSolution6">
 <div class="accordion-body">
 <p>1. Access a single column:</p>
 <div class="codewrapper sourceCode" id="cb42">
@@ -1269,7 +1269,7 @@ <h4 class="accordion-header" id="headingSolution7">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution7" class="accordion-collapse collapse" data-bs-parent="#accordionSolution7" aria-labelledby="headingSolution7">
+<div id="collapseSolution7" class="accordion-collapse collapse" aria-labelledby="headingSolution7" data-bs-parent="#accordionSolution7">
 <div class="accordion-body">
 <p>Among many choices, <code>dir()</code> lists the
 <code>median()</code> function as a possibility. Thus,</p>
@@ -1369,8 +1369,8 @@ <h3 class="callout-title">Keypoints<a class="anchor" aria-label="anchor" href="#
   "url": "https://swcarpentry.github.io/python-novice-gapminder/08-data-frames.html",
   "identifier": "https://swcarpentry.github.io/python-novice-gapminder/08-data-frames.html",
   "dateCreated": "2016-01-07",
-  "dateModified": "2023-06-05",
-  "datePublished": "2023-07-18"
+  "dateModified": "2023-07-24",
+  "datePublished": "2023-07-24"
 }
 
   </script><script>
diff --git a/09-plotting.html b/09-plotting.html
index 21bc3abe8..7bf26cd93 100644
--- a/09-plotting.html
+++ b/09-plotting.html
@@ -912,7 +912,7 @@ <h3 class="callout-title">Keypoints<a class="anchor" aria-label="anchor" href="#
   "identifier": "https://swcarpentry.github.io/python-novice-gapminder/09-plotting.html",
   "dateCreated": "2016-01-07",
   "dateModified": "2023-06-08",
-  "datePublished": "2023-07-18"
+  "datePublished": "2023-07-24"
 }
 
   </script><script>
diff --git a/10-lunch.html b/10-lunch.html
index 363a1bcd6..8291d9f9e 100644
--- a/10-lunch.html
+++ b/10-lunch.html
@@ -442,7 +442,7 @@ <h1>Lunch</h1>
   "identifier": "https://swcarpentry.github.io/python-novice-gapminder/10-lunch.html",
   "dateCreated": "2016-01-07",
   "dateModified": "2023-05-02",
-  "datePublished": "2023-07-18"
+  "datePublished": "2023-07-24"
 }
 
   </script><script>
diff --git a/11-lists.html b/11-lists.html
index 107173d60..596a222fb 100644
--- a/11-lists.html
+++ b/11-lists.html
@@ -1090,7 +1090,7 @@ <h3 class="callout-title">Keypoints<a class="anchor" aria-label="anchor" href="#
   "identifier": "https://swcarpentry.github.io/python-novice-gapminder/11-lists.html",
   "dateCreated": "2016-01-07",
   "dateModified": "2023-05-02",
-  "datePublished": "2023-07-18"
+  "datePublished": "2023-07-24"
 }
 
   </script><script>
diff --git a/12-for-loops.html b/12-for-loops.html
index 5c6100463..57efc2566 100644
--- a/12-for-loops.html
+++ b/12-for-loops.html
@@ -1117,7 +1117,7 @@ <h3 class="callout-title">Keypoints<a class="anchor" aria-label="anchor" href="#
   "identifier": "https://swcarpentry.github.io/python-novice-gapminder/12-for-loops.html",
   "dateCreated": "2016-01-07",
   "dateModified": "2023-05-02",
-  "datePublished": "2023-07-18"
+  "datePublished": "2023-07-24"
 }
 
   </script><script>
diff --git a/13-conditionals.html b/13-conditionals.html
index f012a3c17..2833931ab 100644
--- a/13-conditionals.html
+++ b/13-conditionals.html
@@ -743,7 +743,7 @@ <h4 class="accordion-header" id="headingSolution1">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
 <div class="accordion-body">
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -792,7 +792,7 @@ <h4 class="accordion-header" id="headingSolution2">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
 <div class="accordion-body">
 <div class="codewrapper sourceCode" id="cb22">
 <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -840,7 +840,7 @@ <h4 class="accordion-header" id="headingSolution3">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
 <div class="accordion-body">
 <div class="codewrapper sourceCode" id="cb24">
 <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -891,7 +891,7 @@ <h4 class="accordion-header" id="headingSolution4">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution4" class="accordion-collapse collapse" data-bs-parent="#accordionSolution4" aria-labelledby="headingSolution4">
+<div id="collapseSolution4" class="accordion-collapse collapse" aria-labelledby="headingSolution4" data-bs-parent="#accordionSolution4">
 <div class="accordion-body">
 <div class="codewrapper sourceCode" id="cb26">
 <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1017,7 +1017,7 @@ <h3 class="callout-title">Keypoints<a class="anchor" aria-label="anchor" href="#
   "identifier": "https://swcarpentry.github.io/python-novice-gapminder/13-conditionals.html",
   "dateCreated": "2016-01-07",
   "dateModified": "2023-05-02",
-  "datePublished": "2023-07-18"
+  "datePublished": "2023-07-24"
 }
 
   </script><script>
diff --git a/14-looping-data-sets.html b/14-looping-data-sets.html
index a50af4b30..2ffbed2f0 100644
--- a/14-looping-data-sets.html
+++ b/14-looping-data-sets.html
@@ -545,7 +545,7 @@ <h4 class="accordion-header" id="headingSolution1">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
 <div class="accordion-body">
 <p>1 is not matched by the glob.</p>
 </div>
@@ -586,7 +586,7 @@ <h4 class="accordion-header" id="headingSolution2">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
 <div class="accordion-body">
 <div class="codewrapper sourceCode" id="cb10">
 <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -629,7 +629,7 @@ <h4 class="accordion-header" id="headingSolution3">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
 <div class="accordion-body">
 <p>This solution builds a useful legend by using the <a href="https://docs.python.org/3/library/stdtypes.html#str.split" class="external-link">string
 <code>split</code> method</a> to extract the <code>region</code> from
@@ -762,7 +762,7 @@ <h3 class="callout-title">Keypoints<a class="anchor" aria-label="anchor" href="#
   "identifier": "https://swcarpentry.github.io/python-novice-gapminder/14-looping-data-sets.html",
   "dateCreated": "2016-01-07",
   "dateModified": "2023-05-02",
-  "datePublished": "2023-07-18"
+  "datePublished": "2023-07-24"
 }
 
   </script><script>
diff --git a/15-coffee.html b/15-coffee.html
index d5cefacdb..876c8bccd 100644
--- a/15-coffee.html
+++ b/15-coffee.html
@@ -454,7 +454,7 @@ <h1>Afternoon Coffee</h1>
   "identifier": "https://swcarpentry.github.io/python-novice-gapminder/15-coffee.html",
   "dateCreated": "2016-01-07",
   "dateModified": "2023-05-02",
-  "datePublished": "2023-07-18"
+  "datePublished": "2023-07-24"
 }
 
   </script><script>
diff --git a/16-writing-functions.html b/16-writing-functions.html
index a6d3b4e33..61e647657 100644
--- a/16-writing-functions.html
+++ b/16-writing-functions.html
@@ -384,7 +384,7 @@ <h2 class="accordion-header" id="flush-headingTwelve">
       </div>
       <hr></nav><main id="main-content" class="main-content"><div class="container lesson-content">
         <h1>Writing Functions</h1>
-        <p> Last updated on 2023-05-02 | 
+        <p> Last updated on 2023-07-24 | 
         
         <a href="https://github.com/swcarpentry/python-novice-gapminder/edit/main/episodes/16-writing-functions.md" class="external-link">Edit this page <i aria-hidden="true" data-feather="edit"></i></a></p>
         
@@ -1002,8 +1002,8 @@ <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"><
 </h3>
 <pre class="sourceCode python" tabindex="0"><code class="sourceCode python"><span id="cb35-1"><a href="#cb35-1" aria-hidden="true" tabindex="-1"></a><span class="im">import</span> pandas <span class="im">as</span> pd</span>
 <span id="cb35-2"><a href="#cb35-2" aria-hidden="true" tabindex="-1"></a></span>
-<span id="cb35-3"><a href="#cb35-3" aria-hidden="true" tabindex="-1"></a>df <span class="op">=</span> pd.read_csv(<span class="st">'data/gapminder_gdp_asia.csv'</span>, index_col<span class="op">=</span><span class="dv">0</span>)</span>
-<span id="cb35-4"><a href="#cb35-4" aria-hidden="true" tabindex="-1"></a>japan <span class="op">=</span> df.loc[<span class="st">'Japan'</span>]</span></code></pre>
+<span id="cb35-3"><a href="#cb35-3" aria-hidden="true" tabindex="-1"></a>data_asia <span class="op">=</span> pd.read_csv(<span class="st">'data/gapminder_gdp_asia.csv'</span>, index_col<span class="op">=</span><span class="dv">0</span>)</span>
+<span id="cb35-4"><a href="#cb35-4" aria-hidden="true" tabindex="-1"></a>japan <span class="op">=</span> data_asia.loc[<span class="st">'Japan'</span>]</span></code></pre>
 </div>
 <ol style="list-style-type: decimal"><li>Complete the statements below to obtain the average GDP for Japan
 across the years reported for the 1980s.</li>
@@ -1019,7 +1019,7 @@ <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"><
 <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
 <pre class="sourceCode python" tabindex="0"><code class="sourceCode python"><span id="cb37-1"><a href="#cb37-1" aria-hidden="true" tabindex="-1"></a><span class="kw">def</span> avg_gdp_in_decade(country, continent, year):</span>
-<span id="cb37-2"><a href="#cb37-2" aria-hidden="true" tabindex="-1"></a>    df <span class="op">=</span> pd.read_csv(<span class="st">'data/gapminder_gdp_'</span><span class="op">+</span>___<span class="op">+</span><span class="st">'.csv'</span>,delimiter<span class="op">=</span><span class="st">','</span>,index_col<span class="op">=</span><span class="dv">0</span>)</span>
+<span id="cb37-2"><a href="#cb37-2" aria-hidden="true" tabindex="-1"></a>    data_countries <span class="op">=</span> pd.read_csv(<span class="st">'data/gapminder_gdp_'</span><span class="op">+</span>___<span class="op">+</span><span class="st">'.csv'</span>,delimiter<span class="op">=</span><span class="st">','</span>,index_col<span class="op">=</span><span class="dv">0</span>)</span>
 <span id="cb37-3"><a href="#cb37-3" aria-hidden="true" tabindex="-1"></a>    ____</span>
 <span id="cb37-4"><a href="#cb37-4" aria-hidden="true" tabindex="-1"></a>    ____</span>
 <span id="cb37-5"><a href="#cb37-5" aria-hidden="true" tabindex="-1"></a>    ____</span>
@@ -1056,8 +1056,8 @@ <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"><
 <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
 <pre class="sourceCode python" tabindex="0"><code class="sourceCode python"><span id="cb39-1"><a href="#cb39-1" aria-hidden="true" tabindex="-1"></a><span class="kw">def</span> avg_gdp_in_decade(country, continent, year):</span>
-<span id="cb39-2"><a href="#cb39-2" aria-hidden="true" tabindex="-1"></a>    df <span class="op">=</span> pd.read_csv(<span class="st">'data/gapminder_gdp_'</span> <span class="op">+</span> continent <span class="op">+</span> <span class="st">'.csv'</span>, index_col<span class="op">=</span><span class="dv">0</span>)</span>
-<span id="cb39-3"><a href="#cb39-3" aria-hidden="true" tabindex="-1"></a>    c <span class="op">=</span> df.loc[country]</span>
+<span id="cb39-2"><a href="#cb39-2" aria-hidden="true" tabindex="-1"></a>    data_countries <span class="op">=</span> pd.read_csv(<span class="st">'data/gapminder_gdp_'</span> <span class="op">+</span> continent <span class="op">+</span> <span class="st">'.csv'</span>, index_col<span class="op">=</span><span class="dv">0</span>)</span>
+<span id="cb39-3"><a href="#cb39-3" aria-hidden="true" tabindex="-1"></a>    c <span class="op">=</span> data_countries.loc[country]</span>
 <span id="cb39-4"><a href="#cb39-4" aria-hidden="true" tabindex="-1"></a>    gdp_decade <span class="op">=</span> <span class="st">'gdpPercap_'</span> <span class="op">+</span> <span class="bu">str</span>(year <span class="op">//</span> <span class="dv">10</span>)</span>
 <span id="cb39-5"><a href="#cb39-5" aria-hidden="true" tabindex="-1"></a>    avg <span class="op">=</span> (c.loc[gdp_decade <span class="op">+</span> <span class="st">'2'</span>] <span class="op">+</span> c.loc[gdp_decade <span class="op">+</span> <span class="st">'7'</span>])<span class="op">/</span><span class="dv">2</span></span>
 <span id="cb39-6"><a href="#cb39-6" aria-hidden="true" tabindex="-1"></a>    <span class="cf">return</span> avg</span></code></pre>
@@ -1068,8 +1068,8 @@ <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"><
 <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
 <pre class="sourceCode python" tabindex="0"><code class="sourceCode python"><span id="cb40-1"><a href="#cb40-1" aria-hidden="true" tabindex="-1"></a><span class="kw">def</span> avg_gdp_in_decade(country, continent, year):</span>
-<span id="cb40-2"><a href="#cb40-2" aria-hidden="true" tabindex="-1"></a>    df <span class="op">=</span> pd.read_csv(<span class="st">'data/gapminder_gdp_'</span> <span class="op">+</span> continent <span class="op">+</span> <span class="st">'.csv'</span>, index_col<span class="op">=</span><span class="dv">0</span>)</span>
-<span id="cb40-3"><a href="#cb40-3" aria-hidden="true" tabindex="-1"></a>    c <span class="op">=</span> df.loc[country]</span>
+<span id="cb40-2"><a href="#cb40-2" aria-hidden="true" tabindex="-1"></a>    data_countries <span class="op">=</span> pd.read_csv(<span class="st">'data/gapminder_gdp_'</span> <span class="op">+</span> continent <span class="op">+</span> <span class="st">'.csv'</span>, index_col<span class="op">=</span><span class="dv">0</span>)</span>
+<span id="cb40-3"><a href="#cb40-3" aria-hidden="true" tabindex="-1"></a>    c <span class="op">=</span> data_countries.loc[country]</span>
 <span id="cb40-4"><a href="#cb40-4" aria-hidden="true" tabindex="-1"></a>    gdp_decade <span class="op">=</span> <span class="st">'gdpPercap_'</span> <span class="op">+</span> <span class="bu">str</span>(year <span class="op">//</span> <span class="dv">10</span>)</span>
 <span id="cb40-5"><a href="#cb40-5" aria-hidden="true" tabindex="-1"></a>    total <span class="op">=</span> <span class="fl">0.0</span></span>
 <span id="cb40-6"><a href="#cb40-6" aria-hidden="true" tabindex="-1"></a>    num_years <span class="op">=</span> <span class="dv">0</span></span>
@@ -1308,8 +1308,8 @@ <h3 class="callout-title">Keypoints<a class="anchor" aria-label="anchor" href="#
   "url": "https://swcarpentry.github.io/python-novice-gapminder/16-writing-functions.html",
   "identifier": "https://swcarpentry.github.io/python-novice-gapminder/16-writing-functions.html",
   "dateCreated": "2016-01-07",
-  "dateModified": "2023-05-02",
-  "datePublished": "2023-07-18"
+  "dateModified": "2023-07-24",
+  "datePublished": "2023-07-24"
 }
 
   </script><script>
diff --git a/17-scope.html b/17-scope.html
index 0ea7c38eb..6de8a60b9 100644
--- a/17-scope.html
+++ b/17-scope.html
@@ -538,7 +538,7 @@ <h4 class="accordion-header" id="headingSolution1">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
 <div class="accordion-body">
 <ol style="list-style-type: decimal"><li>Three levels.</li>
 <li><code>errors_02.py</code></li>
@@ -622,7 +622,7 @@ <h3 class="callout-title">Keypoints<a class="anchor" aria-label="anchor" href="#
   "identifier": "https://swcarpentry.github.io/python-novice-gapminder/17-scope.html",
   "dateCreated": "2016-01-07",
   "dateModified": "2023-05-02",
-  "datePublished": "2023-07-18"
+  "datePublished": "2023-07-24"
 }
 
   </script><script>
diff --git a/18-style.html b/18-style.html
index 75f7eca12..4ae6970d9 100644
--- a/18-style.html
+++ b/18-style.html
@@ -587,7 +587,7 @@ <h4 class="accordion-header" id="headingSolution1">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
 <div class="accordion-body">
 <div class="codewrapper sourceCode" id="cb7">
 <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -646,7 +646,7 @@ <h4 class="accordion-header" id="headingSolution2">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
 <div class="accordion-body">
 <p>Here’s one solution.</p>
 <div class="codewrapper sourceCode" id="cb9">
@@ -764,7 +764,7 @@ <h3 class="callout-title">Keypoints<a class="anchor" aria-label="anchor" href="#
   "identifier": "https://swcarpentry.github.io/python-novice-gapminder/18-style.html",
   "dateCreated": "2016-01-07",
   "dateModified": "2023-05-02",
-  "datePublished": "2023-07-18"
+  "datePublished": "2023-07-24"
 }
 
   </script><script>
diff --git a/19-wrap.html b/19-wrap.html
index 35082a789..7a15395cd 100644
--- a/19-wrap.html
+++ b/19-wrap.html
@@ -502,7 +502,7 @@ <h3 class="callout-title">Keypoints<a class="anchor" aria-label="anchor" href="#
   "identifier": "https://swcarpentry.github.io/python-novice-gapminder/19-wrap.html",
   "dateCreated": "2016-01-07",
   "dateModified": "2023-05-02",
-  "datePublished": "2023-07-18"
+  "datePublished": "2023-07-24"
 }
 
   </script><script>
diff --git a/20-feedback.html b/20-feedback.html
index 654009afd..6c72edb7a 100644
--- a/20-feedback.html
+++ b/20-feedback.html
@@ -472,7 +472,7 @@ <h3 class="callout-title">Keypoints<a class="anchor" aria-label="anchor" href="#
   "identifier": "https://swcarpentry.github.io/python-novice-gapminder/20-feedback.html",
   "dateCreated": "2016-01-07",
   "dateModified": "2023-05-02",
-  "datePublished": "2023-07-18"
+  "datePublished": "2023-07-24"
 }
 
   </script><script>
diff --git a/404.html b/404.html
index 0535fe1de..05184a0e1 100644
--- a/404.html
+++ b/404.html
@@ -416,8 +416,8 @@ <h1>Page not found</h1>
   "url": "https://swcarpentry.github.io/python-novice-gapminder/404.html",
   "identifier": "https://swcarpentry.github.io/python-novice-gapminder/404.html",
   "dateCreated": "2016-01-07",
-  "dateModified": "2023-07-18",
-  "datePublished": "2023-07-18"
+  "dateModified": "2023-07-24",
+  "datePublished": "2023-07-24"
 }
 
   </script><script>
diff --git a/CODE_OF_CONDUCT.html b/CODE_OF_CONDUCT.html
index c428a2557..98b019b3f 100644
--- a/CODE_OF_CONDUCT.html
+++ b/CODE_OF_CONDUCT.html
@@ -440,7 +440,7 @@ <h1>Contributor Code of Conduct</h1>
   "identifier": "https://swcarpentry.github.io/python-novice-gapminder/CODE_OF_CONDUCT.html",
   "dateCreated": "2016-01-07",
   "dateModified": "2023-05-02",
-  "datePublished": "2023-07-18"
+  "datePublished": "2023-07-24"
 }
 
   </script><script>
diff --git a/LICENSE.html b/LICENSE.html
index 5e9e56d78..1e1c42c0a 100644
--- a/LICENSE.html
+++ b/LICENSE.html
@@ -491,7 +491,7 @@ <h1>Licenses</h1>
   "identifier": "https://swcarpentry.github.io/python-novice-gapminder/LICENSE.html",
   "dateCreated": "2016-01-07",
   "dateModified": "2023-05-02",
-  "datePublished": "2023-07-18"
+  "datePublished": "2023-07-24"
 }
 
   </script><script>
diff --git a/aio.html b/aio.html
index b9ff0b039..eaa1e0aca 100644
--- a/aio.html
+++ b/aio.html
@@ -830,7 +830,7 @@ <h4 class="accordion-header" id="headingSolution1">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
 <div class="accordion-body">
 <p>After creating the necessary tabs, you can drag one of the tabs to
 the center of a panel to move the tab to the panel; next you can
@@ -902,7 +902,7 @@ <h4 class="accordion-header" id="headingSolution2">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
 <div class="accordion-body">
 <p>Command mode has a grey border and Edit mode has a blue border. Use
 <kbd>Esc</kbd> and <kbd>Return</kbd> to switch between modes. You need
@@ -1093,7 +1093,7 @@ <h4 class="accordion-header" id="headingSolution3">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
 <div class="accordion-body">
 <p>This challenge integrates both the numbered list and bullet list.
 Note that the bullet list is indented 2 spaces so that it is inline with
@@ -1136,7 +1136,7 @@ <h4 class="accordion-header" id="headingSolution4">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution4" class="accordion-collapse collapse" aria-labelledby="headingSolution4" data-bs-parent="#accordionSolution4">
+<div id="collapseSolution4" class="accordion-collapse collapse" data-bs-parent="#accordionSolution4" aria-labelledby="headingSolution4">
 <div class="accordion-body">
 <p>Python returns the output of the last calculation.</p>
 <div class="codewrapper sourceCode" id="cb12">
@@ -1181,7 +1181,7 @@ <h4 class="accordion-header" id="headingSolution5">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution5" class="accordion-collapse collapse" aria-labelledby="headingSolution5" data-bs-parent="#accordionSolution5">
+<div id="collapseSolution5" class="accordion-collapse collapse" data-bs-parent="#accordionSolution5" aria-labelledby="headingSolution5">
 <div class="accordion-body">
 <p>The Python code gets treated like Markdown text. The lines appear as
 if they are part of one contiguous paragraph. This could be useful to
@@ -1221,7 +1221,7 @@ <h4 class="accordion-header" id="headingSolution6">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution6" class="accordion-collapse collapse" aria-labelledby="headingSolution6" data-bs-parent="#accordionSolution6">
+<div id="collapseSolution6" class="accordion-collapse collapse" data-bs-parent="#accordionSolution6" aria-labelledby="headingSolution6">
 <div class="accordion-body">
 <p>The notebook shows the equation as it would be rendered from LaTeX
 equation syntax. The dollar sign, <code>$</code>, is used to tell
@@ -1603,7 +1603,7 @@ <h4 class="accordion-header" id="headingSolution1">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
 <div class="accordion-body">
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1650,7 +1650,7 @@ <h4 class="accordion-header" id="headingSolution2">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
 <div class="accordion-body">
 <div class="codewrapper sourceCode" id="cb20">
 <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1692,7 +1692,7 @@ <h4 class="accordion-header" id="headingSolution3">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
 <div class="accordion-body">
 <p>Numbers are not strings or sequences and Python will raise an error
 if you try to perform an index operation on a number. In the <a href="03-types-conversion.html">next lesson on types and type
@@ -1752,7 +1752,7 @@ <h4 class="accordion-header" id="headingSolution4">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution4" class="accordion-collapse collapse" data-bs-parent="#accordionSolution4" aria-labelledby="headingSolution4">
+<div id="collapseSolution4" class="accordion-collapse collapse" aria-labelledby="headingSolution4" data-bs-parent="#accordionSolution4">
 <div class="accordion-body">
 <p><code>minutes</code> is better because <code>min</code> might mean
 something like “minimum” (and actually is an existing built-in function
@@ -1786,7 +1786,7 @@ <h4 class="accordion-header" id="headingSolution5">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution5" class="accordion-collapse collapse" data-bs-parent="#accordionSolution5" aria-labelledby="headingSolution5">
+<div id="collapseSolution5" class="accordion-collapse collapse" aria-labelledby="headingSolution5" data-bs-parent="#accordionSolution5">
 <div class="accordion-body">
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1838,7 +1838,7 @@ <h4 class="accordion-header" id="headingSolution6">
   Solutions
   </h4>
 </button>
-<div id="collapseSolution6" class="accordion-collapse collapse" data-bs-parent="#accordionSolution6" aria-labelledby="headingSolution6">
+<div id="collapseSolution6" class="accordion-collapse collapse" aria-labelledby="headingSolution6" data-bs-parent="#accordionSolution6">
 <div class="accordion-body">
 <ol style="list-style-type: decimal">
 <li>
@@ -2994,7 +2994,7 @@ <h4 class="accordion-header" id="headingSolution1">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
 <div class="accordion-body">
 <ol style="list-style-type: decimal">
 <li>Order of operations:</li>
@@ -3044,7 +3044,7 @@ <h4 class="accordion-header" id="headingSolution2">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
 <div class="accordion-body">
 <div class="codewrapper sourceCode" id="cb30">
 <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -3112,7 +3112,7 @@ <h4 class="accordion-header" id="headingSolution3">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
 <div class="accordion-body">
 <p><code>max</code> and <code>min</code> return TypeErrors in this case
 because the correct number of parameters was not supplied. If it just
@@ -3145,7 +3145,7 @@ <h4 class="accordion-header" id="headingSolution4">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution4" class="accordion-collapse collapse" aria-labelledby="headingSolution4" data-bs-parent="#accordionSolution4">
+<div id="collapseSolution4" class="accordion-collapse collapse" data-bs-parent="#accordionSolution4" aria-labelledby="headingSolution4">
 <div class="accordion-body">
 <p><code>name[len(name) - 1]</code></p>
 </div>
@@ -3446,7 +3446,7 @@ <h4 class="accordion-header" id="headingSolution1">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
 <div class="accordion-body">
 <ol style="list-style-type: decimal">
 <li><p>Using <code>help(math)</code> we see that we’ve got
@@ -3496,7 +3496,7 @@ <h4 class="accordion-header" id="headingSolution2">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
 <div class="accordion-body">
 <p>The <a href="https://docs.python.org/3/library/random.html" class="external-link">random
 module</a> seems like it could help.</p>
@@ -3578,7 +3578,7 @@ <h4 class="accordion-header" id="headingSolution3">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
 <div class="accordion-body">
 <div class="codewrapper sourceCode" id="cb15">
 <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -3620,7 +3620,7 @@ <h4 class="accordion-header" id="headingSolution4">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution4" class="accordion-collapse collapse" aria-labelledby="headingSolution4" data-bs-parent="#accordionSolution4">
+<div id="collapseSolution4" class="accordion-collapse collapse" data-bs-parent="#accordionSolution4" aria-labelledby="headingSolution4">
 <div class="accordion-body">
 <p>Importing the math module (<code>import math</code>)</p>
 </div>
@@ -3659,7 +3659,7 @@ <h4 class="accordion-header" id="headingSolution5">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution5" class="accordion-collapse collapse" aria-labelledby="headingSolution5" data-bs-parent="#accordionSolution5">
+<div id="collapseSolution5" class="accordion-collapse collapse" data-bs-parent="#accordionSolution5" aria-labelledby="headingSolution5">
 <div class="accordion-body">
 <div class="codewrapper sourceCode" id="cb18">
 <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -3719,7 +3719,7 @@ <h4 class="accordion-header" id="headingSolution6">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution6" class="accordion-collapse collapse" aria-labelledby="headingSolution6" data-bs-parent="#accordionSolution6">
+<div id="collapseSolution6" class="accordion-collapse collapse" data-bs-parent="#accordionSolution6" aria-labelledby="headingSolution6">
 <div class="accordion-body">
 <ol style="list-style-type: decimal">
 <li>Library calls 1 and 4. In order to directly refer to
@@ -3781,7 +3781,7 @@ <h4 class="accordion-header" id="headingSolution7">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution7" class="accordion-collapse collapse" aria-labelledby="headingSolution7" data-bs-parent="#accordionSolution7">
+<div id="collapseSolution7" class="accordion-collapse collapse" data-bs-parent="#accordionSolution7" aria-labelledby="headingSolution7">
 <div class="accordion-body">
 <div class="codewrapper sourceCode" id="cb21">
 <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -3830,7 +3830,7 @@ <h4 class="accordion-header" id="headingSolution8">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution8" class="accordion-collapse collapse" aria-labelledby="headingSolution8" data-bs-parent="#accordionSolution8">
+<div id="collapseSolution8" class="accordion-collapse collapse" data-bs-parent="#accordionSolution8" aria-labelledby="headingSolution8">
 <div class="accordion-body">
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -4478,7 +4478,7 @@ <h3 class="callout-title">Keypoints<a class="anchor" aria-label="anchor" href="#
 </div>
 </section></section><section id="aio-08-data-frames"><p>Content from <a href="08-data-frames.html">Pandas DataFrames</a></p>
 <hr>
-<p> Last updated on 2023-06-05 | 
+<p> Last updated on 2023-07-24 | 
         
         <a href="https://github.com/swcarpentry/python-novice-gapminder/edit/main/episodes/08-data-frames.md" class="external-link">Edit this page <i aria-hidden="true" data-feather="edit"></i></a></p>
 <div class="text-end">
@@ -4878,7 +4878,7 @@ <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"><
 </h3>
 <pre class="sourceCode python" tabindex="0"><code class="sourceCode python"><span id="cb25-1"><a href="#cb25-1" aria-hidden="true" tabindex="-1"></a><span class="im">import</span> pandas <span class="im">as</span> pd</span>
 <span id="cb25-2"><a href="#cb25-2" aria-hidden="true" tabindex="-1"></a></span>
-<span id="cb25-3"><a href="#cb25-3" aria-hidden="true" tabindex="-1"></a>df <span class="op">=</span> pd.read_csv(<span class="st">'data/gapminder_gdp_europe.csv'</span>, index_col<span class="op">=</span><span class="st">'country'</span>)</span></code></pre>
+<span id="cb25-3"><a href="#cb25-3" aria-hidden="true" tabindex="-1"></a>data_europe <span class="op">=</span> pd.read_csv(<span class="st">'data/gapminder_gdp_europe.csv'</span>, index_col<span class="op">=</span><span class="st">'country'</span>)</span></code></pre>
 </div>
 <p>Write an expression to find the Per Capita GDP of Serbia in 2007.</p>
 </div>
@@ -4891,14 +4891,14 @@ <h4 class="accordion-header" id="headingSolution1">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
 <div class="accordion-body">
 <p>The selection can be done by using the labels for both the row
 (“Serbia”) and the column (“gdpPercap_2007”):</p>
 <div class="codewrapper sourceCode" id="cb26">
 <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode python" tabindex="0"><code class="sourceCode python"><span id="cb26-1"><a href="#cb26-1" aria-hidden="true" tabindex="-1"></a><span class="bu">print</span>(df.loc[<span class="st">'Serbia'</span>, <span class="st">'gdpPercap_2007'</span>])</span></code></pre>
+<pre class="sourceCode python" tabindex="0"><code class="sourceCode python"><span id="cb26-1"><a href="#cb26-1" aria-hidden="true" tabindex="-1"></a><span class="bu">print</span>(data_europe.loc[<span class="st">'Serbia'</span>, <span class="st">'gdpPercap_2007'</span>])</span></code></pre>
 </div>
 <p>The output is</p>
 <div class="codewrapper">
@@ -4926,8 +4926,8 @@ <h3 class="callout-title">Extent of Slicing<a class="anchor" aria-label="anchor"
 <div class="codewrapper sourceCode" id="cb28">
 <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode python" tabindex="0"><code class="sourceCode python"><span id="cb28-1"><a href="#cb28-1" aria-hidden="true" tabindex="-1"></a><span class="bu">print</span>(df.iloc[<span class="dv">0</span>:<span class="dv">2</span>, <span class="dv">0</span>:<span class="dv">2</span>])</span>
-<span id="cb28-2"><a href="#cb28-2" aria-hidden="true" tabindex="-1"></a><span class="bu">print</span>(df.loc[<span class="st">'Albania'</span>:<span class="st">'Belgium'</span>, <span class="st">'gdpPercap_1952'</span>:<span class="st">'gdpPercap_1962'</span>])</span></code></pre>
+<pre class="sourceCode python" tabindex="0"><code class="sourceCode python"><span id="cb28-1"><a href="#cb28-1" aria-hidden="true" tabindex="-1"></a><span class="bu">print</span>(data_europe.iloc[<span class="dv">0</span>:<span class="dv">2</span>, <span class="dv">0</span>:<span class="dv">2</span>])</span>
+<span id="cb28-2"><a href="#cb28-2" aria-hidden="true" tabindex="-1"></a><span class="bu">print</span>(data_europe.loc[<span class="st">'Albania'</span>:<span class="st">'Belgium'</span>, <span class="st">'gdpPercap_1952'</span>:<span class="st">'gdpPercap_1962'</span>])</span></code></pre>
 </div>
 </div>
 </div>
@@ -4939,7 +4939,7 @@ <h4 class="accordion-header" id="headingSolution2">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
 <div class="accordion-body">
 <p>No, they do not produce the same output! The output of the first
 statement is:</p>
@@ -5000,7 +5000,7 @@ <h4 class="accordion-header" id="headingSolution3">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
 <div class="accordion-body">
 <p>Let’s go through this piece of code line by line.</p>
 <div class="codewrapper sourceCode" id="cb32">
@@ -5084,7 +5084,7 @@ <h4 class="accordion-header" id="headingSolution4">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution4" class="accordion-collapse collapse" data-bs-parent="#accordionSolution4" aria-labelledby="headingSolution4">
+<div id="collapseSolution4" class="accordion-collapse collapse" aria-labelledby="headingSolution4" data-bs-parent="#accordionSolution4">
 <div class="accordion-body">
 <p>For each column in <code>data</code>, <code>idxmin</code> will return
 the index value corresponding to each column’s minimum;
@@ -5124,7 +5124,7 @@ <h4 class="accordion-header" id="headingSolution5">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution5" class="accordion-collapse collapse" data-bs-parent="#accordionSolution5" aria-labelledby="headingSolution5">
+<div id="collapseSolution5" class="accordion-collapse collapse" aria-labelledby="headingSolution5" data-bs-parent="#accordionSolution5">
 <div class="accordion-body">
 <p>1:</p>
 <div class="codewrapper sourceCode" id="cb38">
@@ -5203,7 +5203,7 @@ <h4 class="accordion-header" id="headingSolution6">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution6" class="accordion-collapse collapse" data-bs-parent="#accordionSolution6" aria-labelledby="headingSolution6">
+<div id="collapseSolution6" class="accordion-collapse collapse" aria-labelledby="headingSolution6" data-bs-parent="#accordionSolution6">
 <div class="accordion-body">
 <p>1. Access a single column:</p>
 <div class="codewrapper sourceCode" id="cb42">
@@ -5392,7 +5392,7 @@ <h4 class="accordion-header" id="headingSolution7">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution7" class="accordion-collapse collapse" data-bs-parent="#accordionSolution7" aria-labelledby="headingSolution7">
+<div id="collapseSolution7" class="accordion-collapse collapse" aria-labelledby="headingSolution7" data-bs-parent="#accordionSolution7">
 <div class="accordion-body">
 <p>Among many choices, <code>dir()</code> lists the
 <code>median()</code> function as a possibility. Thus,</p>
@@ -7809,7 +7809,7 @@ <h4 class="accordion-header" id="headingSolution1">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
 <div class="accordion-body">
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -7858,7 +7858,7 @@ <h4 class="accordion-header" id="headingSolution2">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
 <div class="accordion-body">
 <div class="codewrapper sourceCode" id="cb22">
 <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -7906,7 +7906,7 @@ <h4 class="accordion-header" id="headingSolution3">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
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 <div class="codewrapper sourceCode" id="cb24">
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@@ -7957,7 +7957,7 @@ <h4 class="accordion-header" id="headingSolution4">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution4" class="accordion-collapse collapse" data-bs-parent="#accordionSolution4" aria-labelledby="headingSolution4">
+<div id="collapseSolution4" class="accordion-collapse collapse" aria-labelledby="headingSolution4" data-bs-parent="#accordionSolution4">
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@@ -8210,7 +8210,7 @@ <h4 class="accordion-header" id="headingSolution1">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
 <div class="accordion-body">
 <p>1 is not matched by the glob.</p>
 </div>
@@ -8251,7 +8251,7 @@ <h4 class="accordion-header" id="headingSolution2">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
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 <div class="codewrapper sourceCode" id="cb10">
 <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -8294,7 +8294,7 @@ <h4 class="accordion-header" id="headingSolution3">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
 <div class="accordion-body">
 <p>This solution builds a useful legend by using the <a href="https://docs.python.org/3/library/stdtypes.html#str.split" class="external-link">string
 <code>split</code> method</a> to extract the <code>region</code> from
@@ -8400,7 +8400,7 @@ <h3 class="callout-title">Keypoints<a class="anchor" aria-label="anchor" href="#
 definition?</li>
 </ul></section></section><section id="aio-16-writing-functions"><p>Content from <a href="16-writing-functions.html">Writing Functions</a></p>
 <hr>
-<p> Last updated on 2023-05-02 | 
+<p> Last updated on 2023-07-24 | 
         
         <a href="https://github.com/swcarpentry/python-novice-gapminder/edit/main/episodes/16-writing-functions.md" class="external-link">Edit this page <i aria-hidden="true" data-feather="edit"></i></a></p>
 <div class="text-end">
@@ -9065,8 +9065,8 @@ <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"><
 </h3>
 <pre class="sourceCode python" tabindex="0"><code class="sourceCode python"><span id="cb35-1"><a href="#cb35-1" aria-hidden="true" tabindex="-1"></a><span class="im">import</span> pandas <span class="im">as</span> pd</span>
 <span id="cb35-2"><a href="#cb35-2" aria-hidden="true" tabindex="-1"></a></span>
-<span id="cb35-3"><a href="#cb35-3" aria-hidden="true" tabindex="-1"></a>df <span class="op">=</span> pd.read_csv(<span class="st">'data/gapminder_gdp_asia.csv'</span>, index_col<span class="op">=</span><span class="dv">0</span>)</span>
-<span id="cb35-4"><a href="#cb35-4" aria-hidden="true" tabindex="-1"></a>japan <span class="op">=</span> df.loc[<span class="st">'Japan'</span>]</span></code></pre>
+<span id="cb35-3"><a href="#cb35-3" aria-hidden="true" tabindex="-1"></a>data_asia <span class="op">=</span> pd.read_csv(<span class="st">'data/gapminder_gdp_asia.csv'</span>, index_col<span class="op">=</span><span class="dv">0</span>)</span>
+<span id="cb35-4"><a href="#cb35-4" aria-hidden="true" tabindex="-1"></a>japan <span class="op">=</span> data_asia.loc[<span class="st">'Japan'</span>]</span></code></pre>
 </div>
 <ol style="list-style-type: decimal">
 <li>Complete the statements below to obtain the average GDP for Japan
@@ -9086,7 +9086,7 @@ <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"><
 <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
 <pre class="sourceCode python" tabindex="0"><code class="sourceCode python"><span id="cb37-1"><a href="#cb37-1" aria-hidden="true" tabindex="-1"></a><span class="kw">def</span> avg_gdp_in_decade(country, continent, year):</span>
-<span id="cb37-2"><a href="#cb37-2" aria-hidden="true" tabindex="-1"></a>    df <span class="op">=</span> pd.read_csv(<span class="st">'data/gapminder_gdp_'</span><span class="op">+</span>___<span class="op">+</span><span class="st">'.csv'</span>,delimiter<span class="op">=</span><span class="st">','</span>,index_col<span class="op">=</span><span class="dv">0</span>)</span>
+<span id="cb37-2"><a href="#cb37-2" aria-hidden="true" tabindex="-1"></a>    data_countries <span class="op">=</span> pd.read_csv(<span class="st">'data/gapminder_gdp_'</span><span class="op">+</span>___<span class="op">+</span><span class="st">'.csv'</span>,delimiter<span class="op">=</span><span class="st">','</span>,index_col<span class="op">=</span><span class="dv">0</span>)</span>
 <span id="cb37-3"><a href="#cb37-3" aria-hidden="true" tabindex="-1"></a>    ____</span>
 <span id="cb37-4"><a href="#cb37-4" aria-hidden="true" tabindex="-1"></a>    ____</span>
 <span id="cb37-5"><a href="#cb37-5" aria-hidden="true" tabindex="-1"></a>    ____</span>
@@ -9129,8 +9129,8 @@ <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"><
 <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
 <pre class="sourceCode python" tabindex="0"><code class="sourceCode python"><span id="cb39-1"><a href="#cb39-1" aria-hidden="true" tabindex="-1"></a><span class="kw">def</span> avg_gdp_in_decade(country, continent, year):</span>
-<span id="cb39-2"><a href="#cb39-2" aria-hidden="true" tabindex="-1"></a>    df <span class="op">=</span> pd.read_csv(<span class="st">'data/gapminder_gdp_'</span> <span class="op">+</span> continent <span class="op">+</span> <span class="st">'.csv'</span>, index_col<span class="op">=</span><span class="dv">0</span>)</span>
-<span id="cb39-3"><a href="#cb39-3" aria-hidden="true" tabindex="-1"></a>    c <span class="op">=</span> df.loc[country]</span>
+<span id="cb39-2"><a href="#cb39-2" aria-hidden="true" tabindex="-1"></a>    data_countries <span class="op">=</span> pd.read_csv(<span class="st">'data/gapminder_gdp_'</span> <span class="op">+</span> continent <span class="op">+</span> <span class="st">'.csv'</span>, index_col<span class="op">=</span><span class="dv">0</span>)</span>
+<span id="cb39-3"><a href="#cb39-3" aria-hidden="true" tabindex="-1"></a>    c <span class="op">=</span> data_countries.loc[country]</span>
 <span id="cb39-4"><a href="#cb39-4" aria-hidden="true" tabindex="-1"></a>    gdp_decade <span class="op">=</span> <span class="st">'gdpPercap_'</span> <span class="op">+</span> <span class="bu">str</span>(year <span class="op">//</span> <span class="dv">10</span>)</span>
 <span id="cb39-5"><a href="#cb39-5" aria-hidden="true" tabindex="-1"></a>    avg <span class="op">=</span> (c.loc[gdp_decade <span class="op">+</span> <span class="st">'2'</span>] <span class="op">+</span> c.loc[gdp_decade <span class="op">+</span> <span class="st">'7'</span>])<span class="op">/</span><span class="dv">2</span></span>
 <span id="cb39-6"><a href="#cb39-6" aria-hidden="true" tabindex="-1"></a>    <span class="cf">return</span> avg</span></code></pre>
@@ -9143,8 +9143,8 @@ <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"><
 <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
 <pre class="sourceCode python" tabindex="0"><code class="sourceCode python"><span id="cb40-1"><a href="#cb40-1" aria-hidden="true" tabindex="-1"></a><span class="kw">def</span> avg_gdp_in_decade(country, continent, year):</span>
-<span id="cb40-2"><a href="#cb40-2" aria-hidden="true" tabindex="-1"></a>    df <span class="op">=</span> pd.read_csv(<span class="st">'data/gapminder_gdp_'</span> <span class="op">+</span> continent <span class="op">+</span> <span class="st">'.csv'</span>, index_col<span class="op">=</span><span class="dv">0</span>)</span>
-<span id="cb40-3"><a href="#cb40-3" aria-hidden="true" tabindex="-1"></a>    c <span class="op">=</span> df.loc[country]</span>
+<span id="cb40-2"><a href="#cb40-2" aria-hidden="true" tabindex="-1"></a>    data_countries <span class="op">=</span> pd.read_csv(<span class="st">'data/gapminder_gdp_'</span> <span class="op">+</span> continent <span class="op">+</span> <span class="st">'.csv'</span>, index_col<span class="op">=</span><span class="dv">0</span>)</span>
+<span id="cb40-3"><a href="#cb40-3" aria-hidden="true" tabindex="-1"></a>    c <span class="op">=</span> data_countries.loc[country]</span>
 <span id="cb40-4"><a href="#cb40-4" aria-hidden="true" tabindex="-1"></a>    gdp_decade <span class="op">=</span> <span class="st">'gdpPercap_'</span> <span class="op">+</span> <span class="bu">str</span>(year <span class="op">//</span> <span class="dv">10</span>)</span>
 <span id="cb40-5"><a href="#cb40-5" aria-hidden="true" tabindex="-1"></a>    total <span class="op">=</span> <span class="fl">0.0</span></span>
 <span id="cb40-6"><a href="#cb40-6" aria-hidden="true" tabindex="-1"></a>    num_years <span class="op">=</span> <span class="dv">0</span></span>
@@ -9510,7 +9510,7 @@ <h4 class="accordion-header" id="headingSolution1">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
 <div class="accordion-body">
 <ol style="list-style-type: decimal">
 <li>Three levels.</li>
@@ -9758,7 +9758,7 @@ <h4 class="accordion-header" id="headingSolution1">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
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 <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -9819,7 +9819,7 @@ <h4 class="accordion-header" id="headingSolution2">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
 <div class="accordion-body">
 <p>Here’s one solution.</p>
 <div class="codewrapper sourceCode" id="cb9">
@@ -10057,8 +10057,8 @@ <h3 class="callout-title">Keypoints<a class="anchor" aria-label="anchor" href="#
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   "identifier": "https://swcarpentry.github.io/python-novice-gapminder/aio.html",
   "dateCreated": "2016-01-07",
-  "dateModified": "2023-07-18",
-  "datePublished": "2023-07-18"
+  "dateModified": "2023-07-24",
+  "datePublished": "2023-07-24"
 }
 
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diff --git a/design.html b/design.html
index 85230ae3f..ee78b0080 100644
--- a/design.html
+++ b/design.html
@@ -926,7 +926,7 @@ <h3 id="finish-1630">Finish (16:30)<a class="anchor" aria-label="anchor" href="#
   "identifier": "https://swcarpentry.github.io/python-novice-gapminder/design.html",
   "dateCreated": "2016-01-07",
   "dateModified": "2023-05-02",
-  "datePublished": "2023-07-18"
+  "datePublished": "2023-07-24"
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diff --git a/discuss.html b/discuss.html
index 92653d4c3..ea67230de 100644
--- a/discuss.html
+++ b/discuss.html
@@ -433,7 +433,7 @@ <h1>Discussion</h1>
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   "dateCreated": "2016-01-07",
   "dateModified": "2023-05-02",
-  "datePublished": "2023-07-18"
+  "datePublished": "2023-07-24"
 }
 
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diff --git a/exercises.html b/exercises.html
index 1e4b4e998..d3e90b68c 100644
--- a/exercises.html
+++ b/exercises.html
@@ -433,7 +433,7 @@ <h1>Further Exercises</h1>
   "identifier": "https://swcarpentry.github.io/python-novice-gapminder/exercises.html",
   "dateCreated": "2016-01-07",
   "dateModified": "2023-05-02",
-  "datePublished": "2023-07-18"
+  "datePublished": "2023-07-24"
 }
 
   </script><script>
diff --git a/images.html b/images.html
index f75cc7bf8..a08982e92 100644
--- a/images.html
+++ b/images.html
@@ -611,8 +611,8 @@ <h3 id="09-plotting-figure-12">Figure 12</h3>
   "url": "https://swcarpentry.github.io/python-novice-gapminder/images.html",
   "identifier": "https://swcarpentry.github.io/python-novice-gapminder/images.html",
   "dateCreated": "2016-01-07",
-  "dateModified": "2023-07-18",
-  "datePublished": "2023-07-18"
+  "dateModified": "2023-07-24",
+  "datePublished": "2023-07-24"
 }
 
   </script><script>
diff --git a/index.html b/index.html
index 29efb40af..8472a683c 100644
--- a/index.html
+++ b/index.html
@@ -463,8 +463,8 @@ <h3 class="callout-title">Prerequisites<a class="anchor" aria-label="anchor" hre
   "url": "https://swcarpentry.github.io/python-novice-gapminder/index.html",
   "identifier": "https://swcarpentry.github.io/python-novice-gapminder/index.html",
   "dateCreated": "2016-01-07",
-  "dateModified": "2023-07-18",
-  "datePublished": "2023-07-18"
+  "dateModified": "2023-07-24",
+  "datePublished": "2023-07-24"
 }
 
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diff --git a/instructor-notes.html b/instructor-notes.html
index cc0f70ef6..287b43adc 100644
--- a/instructor-notes.html
+++ b/instructor-notes.html
@@ -540,8 +540,8 @@ <h1>Instructor Notes</h1>
   "url": "https://swcarpentry.github.io/python-novice-gapminder/instructor-notes.html",
   "identifier": "https://swcarpentry.github.io/python-novice-gapminder/instructor-notes.html",
   "dateCreated": "2016-01-07",
-  "dateModified": "2023-07-18",
-  "datePublished": "2023-07-18"
+  "dateModified": "2023-07-24",
+  "datePublished": "2023-07-24"
 }
 
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diff --git a/instructor/01-run-quit.html b/instructor/01-run-quit.html
index 399d4a713..1c4cd0383 100644
--- a/instructor/01-run-quit.html
+++ b/instructor/01-run-quit.html
@@ -720,7 +720,7 @@ <h4 class="accordion-header" id="headingSolution1">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
 <div class="accordion-body">
 <p>After creating the necessary tabs, you can drag one of the tabs to
 the center of a panel to move the tab to the panel; next you can
@@ -787,7 +787,7 @@ <h4 class="accordion-header" id="headingSolution2">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
 <div class="accordion-body">
 <p>Command mode has a grey border and Edit mode has a blue border. Use
 <kbd>Esc</kbd> and <kbd>Return</kbd> to switch between modes. You need
@@ -951,7 +951,7 @@ <h4 class="accordion-header" id="headingSolution3">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
 <div class="accordion-body">
 <p>This challenge integrates both the numbered list and bullet list.
 Note that the bullet list is indented 2 spaces so that it is inline with
@@ -994,7 +994,7 @@ <h4 class="accordion-header" id="headingSolution4">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution4" class="accordion-collapse collapse" aria-labelledby="headingSolution4" data-bs-parent="#accordionSolution4">
+<div id="collapseSolution4" class="accordion-collapse collapse" data-bs-parent="#accordionSolution4" aria-labelledby="headingSolution4">
 <div class="accordion-body">
 <p>Python returns the output of the last calculation.</p>
 <div class="codewrapper sourceCode" id="cb12">
@@ -1039,7 +1039,7 @@ <h4 class="accordion-header" id="headingSolution5">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution5" class="accordion-collapse collapse" aria-labelledby="headingSolution5" data-bs-parent="#accordionSolution5">
+<div id="collapseSolution5" class="accordion-collapse collapse" data-bs-parent="#accordionSolution5" aria-labelledby="headingSolution5">
 <div class="accordion-body">
 <p>The Python code gets treated like Markdown text. The lines appear as
 if they are part of one contiguous paragraph. This could be useful to
@@ -1079,7 +1079,7 @@ <h4 class="accordion-header" id="headingSolution6">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution6" class="accordion-collapse collapse" aria-labelledby="headingSolution6" data-bs-parent="#accordionSolution6">
+<div id="collapseSolution6" class="accordion-collapse collapse" data-bs-parent="#accordionSolution6" aria-labelledby="headingSolution6">
 <div class="accordion-body">
 <p>The notebook shows the equation as it would be rendered from LaTeX
 equation syntax. The dollar sign, <code>$</code>, is used to tell
@@ -1190,7 +1190,7 @@ <h3 class="callout-title">Keypoints<a class="anchor" aria-label="anchor" href="#
   "identifier": "https://swcarpentry.github.io/python-novice-gapminder/instructor/01-run-quit.html",
   "dateCreated": "2016-01-07",
   "dateModified": "2023-06-07",
-  "datePublished": "2023-07-18"
+  "datePublished": "2023-07-24"
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   </script><script>
diff --git a/instructor/02-variables.html b/instructor/02-variables.html
index 069de791a..e46aeed6e 100644
--- a/instructor/02-variables.html
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@@ -674,7 +674,7 @@ <h4 class="accordion-header" id="headingSolution1">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
 <div class="accordion-body">
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -721,7 +721,7 @@ <h4 class="accordion-header" id="headingSolution2">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
 <div class="accordion-body">
 <div class="codewrapper sourceCode" id="cb20">
 <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -763,7 +763,7 @@ <h4 class="accordion-header" id="headingSolution3">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
 <div class="accordion-body">
 <p>Numbers are not strings or sequences and Python will raise an error
 if you try to perform an index operation on a number. In the <a href="03-types-conversion.html">next lesson on types and type
@@ -821,7 +821,7 @@ <h4 class="accordion-header" id="headingSolution4">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution4" class="accordion-collapse collapse" data-bs-parent="#accordionSolution4" aria-labelledby="headingSolution4">
+<div id="collapseSolution4" class="accordion-collapse collapse" aria-labelledby="headingSolution4" data-bs-parent="#accordionSolution4">
 <div class="accordion-body">
 <p><code>minutes</code> is better because <code>min</code> might mean
 something like “minimum” (and actually is an existing built-in function
@@ -855,7 +855,7 @@ <h4 class="accordion-header" id="headingSolution5">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution5" class="accordion-collapse collapse" data-bs-parent="#accordionSolution5" aria-labelledby="headingSolution5">
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 <div class="accordion-body">
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -905,7 +905,7 @@ <h4 class="accordion-header" id="headingSolution6">
   Solutions
   </h4>
 </button>
-<div id="collapseSolution6" class="accordion-collapse collapse" data-bs-parent="#accordionSolution6" aria-labelledby="headingSolution6">
+<div id="collapseSolution6" class="accordion-collapse collapse" aria-labelledby="headingSolution6" data-bs-parent="#accordionSolution6">
 <div class="accordion-body">
 <ol style="list-style-type: decimal"><li>
 <code>species_name[2:8]</code> returns the substring
@@ -1014,7 +1014,7 @@ <h3 class="callout-title">Keypoints<a class="anchor" aria-label="anchor" href="#
   "identifier": "https://swcarpentry.github.io/python-novice-gapminder/instructor/02-variables.html",
   "dateCreated": "2016-01-07",
   "dateModified": "2023-05-02",
-  "datePublished": "2023-07-18"
+  "datePublished": "2023-07-24"
 }
 
   </script><script>
diff --git a/instructor/03-types-conversion.html b/instructor/03-types-conversion.html
index 7319c40f8..d48c58235 100644
--- a/instructor/03-types-conversion.html
+++ b/instructor/03-types-conversion.html
@@ -1094,7 +1094,7 @@ <h3 class="callout-title">Keypoints<a class="anchor" aria-label="anchor" href="#
   "identifier": "https://swcarpentry.github.io/python-novice-gapminder/instructor/03-types-conversion.html",
   "dateCreated": "2016-01-07",
   "dateModified": "2023-05-02",
-  "datePublished": "2023-07-18"
+  "datePublished": "2023-07-24"
 }
 
   </script><script>
diff --git a/instructor/04-built-in.html b/instructor/04-built-in.html
index f23c9993b..150696a8d 100644
--- a/instructor/04-built-in.html
+++ b/instructor/04-built-in.html
@@ -738,7 +738,7 @@ <h4 class="accordion-header" id="headingSolution1">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
 <div class="accordion-body">
 <ol style="list-style-type: decimal"><li>Order of operations:</li>
 <li><code>1.1 * radiance = 1.1</code></li>
@@ -784,7 +784,7 @@ <h4 class="accordion-header" id="headingSolution2">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
 <div class="accordion-body">
 <div class="codewrapper sourceCode" id="cb30">
 <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -852,7 +852,7 @@ <h4 class="accordion-header" id="headingSolution3">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
 <div class="accordion-body">
 <p><code>max</code> and <code>min</code> return TypeErrors in this case
 because the correct number of parameters was not supplied. If it just
@@ -885,7 +885,7 @@ <h4 class="accordion-header" id="headingSolution4">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution4" class="accordion-collapse collapse" aria-labelledby="headingSolution4" data-bs-parent="#accordionSolution4">
+<div id="collapseSolution4" class="accordion-collapse collapse" data-bs-parent="#accordionSolution4" aria-labelledby="headingSolution4">
 <div class="accordion-body">
 <p><code>name[len(name) - 1]</code></p>
 </div>
@@ -993,7 +993,7 @@ <h3 class="callout-title">Keypoints<a class="anchor" aria-label="anchor" href="#
   "identifier": "https://swcarpentry.github.io/python-novice-gapminder/instructor/04-built-in.html",
   "dateCreated": "2016-01-07",
   "dateModified": "2023-05-02",
-  "datePublished": "2023-07-18"
+  "datePublished": "2023-07-24"
 }
 
   </script><script>
diff --git a/instructor/05-coffee.html b/instructor/05-coffee.html
index d327482d7..c653607fe 100644
--- a/instructor/05-coffee.html
+++ b/instructor/05-coffee.html
@@ -451,7 +451,7 @@ <h1>Morning Coffee</h1>
   "identifier": "https://swcarpentry.github.io/python-novice-gapminder/instructor/05-coffee.html",
   "dateCreated": "2016-01-07",
   "dateModified": "2023-05-02",
-  "datePublished": "2023-07-18"
+  "datePublished": "2023-07-24"
 }
 
   </script><script>
diff --git a/instructor/06-libraries.html b/instructor/06-libraries.html
index 10842f493..243fcd2a9 100644
--- a/instructor/06-libraries.html
+++ b/instructor/06-libraries.html
@@ -585,7 +585,7 @@ <h4 class="accordion-header" id="headingSolution1">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
 <div class="accordion-body">
 <ol style="list-style-type: decimal"><li><p>Using <code>help(math)</code> we see that we’ve got
 <code>pow(x,y)</code> in addition to <code>sqrt(x)</code>, so we could
@@ -631,7 +631,7 @@ <h4 class="accordion-header" id="headingSolution2">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
 <div class="accordion-body">
 <p>The <a href="https://docs.python.org/3/library/random.html" class="external-link">random
 module</a> seems like it could help.</p>
@@ -713,7 +713,7 @@ <h4 class="accordion-header" id="headingSolution3">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
 <div class="accordion-body">
 <div class="codewrapper sourceCode" id="cb15">
 <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -755,7 +755,7 @@ <h4 class="accordion-header" id="headingSolution4">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution4" class="accordion-collapse collapse" aria-labelledby="headingSolution4" data-bs-parent="#accordionSolution4">
+<div id="collapseSolution4" class="accordion-collapse collapse" data-bs-parent="#accordionSolution4" aria-labelledby="headingSolution4">
 <div class="accordion-body">
 <p>Importing the math module (<code>import math</code>)</p>
 </div>
@@ -792,7 +792,7 @@ <h4 class="accordion-header" id="headingSolution5">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution5" class="accordion-collapse collapse" aria-labelledby="headingSolution5" data-bs-parent="#accordionSolution5">
+<div id="collapseSolution5" class="accordion-collapse collapse" data-bs-parent="#accordionSolution5" aria-labelledby="headingSolution5">
 <div class="accordion-body">
 <div class="codewrapper sourceCode" id="cb18">
 <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -848,7 +848,7 @@ <h4 class="accordion-header" id="headingSolution6">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution6" class="accordion-collapse collapse" aria-labelledby="headingSolution6" data-bs-parent="#accordionSolution6">
+<div id="collapseSolution6" class="accordion-collapse collapse" data-bs-parent="#accordionSolution6" aria-labelledby="headingSolution6">
 <div class="accordion-body">
 <ol style="list-style-type: decimal"><li>Library calls 1 and 4. In order to directly refer to
 <code>sin</code> and <code>pi</code> without the library name as prefix,
@@ -906,7 +906,7 @@ <h4 class="accordion-header" id="headingSolution7">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution7" class="accordion-collapse collapse" aria-labelledby="headingSolution7" data-bs-parent="#accordionSolution7">
+<div id="collapseSolution7" class="accordion-collapse collapse" data-bs-parent="#accordionSolution7" aria-labelledby="headingSolution7">
 <div class="accordion-body">
 <div class="codewrapper sourceCode" id="cb21">
 <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -953,7 +953,7 @@ <h4 class="accordion-header" id="headingSolution8">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution8" class="accordion-collapse collapse" aria-labelledby="headingSolution8" data-bs-parent="#accordionSolution8">
+<div id="collapseSolution8" class="accordion-collapse collapse" data-bs-parent="#accordionSolution8" aria-labelledby="headingSolution8">
 <div class="accordion-body">
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1048,7 +1048,7 @@ <h3 class="callout-title">Keypoints<a class="anchor" aria-label="anchor" href="#
   "identifier": "https://swcarpentry.github.io/python-novice-gapminder/instructor/06-libraries.html",
   "dateCreated": "2016-01-07",
   "dateModified": "2023-05-02",
-  "datePublished": "2023-07-18"
+  "datePublished": "2023-07-24"
 }
 
   </script><script>
diff --git a/instructor/07-reading-tabular.html b/instructor/07-reading-tabular.html
index d6c8da8ed..016f5d4ab 100644
--- a/instructor/07-reading-tabular.html
+++ b/instructor/07-reading-tabular.html
@@ -1007,7 +1007,7 @@ <h3 class="callout-title">Keypoints<a class="anchor" aria-label="anchor" href="#
   "identifier": "https://swcarpentry.github.io/python-novice-gapminder/instructor/07-reading-tabular.html",
   "dateCreated": "2016-01-07",
   "dateModified": "2023-05-02",
-  "datePublished": "2023-07-18"
+  "datePublished": "2023-07-24"
 }
 
   </script><script>
diff --git a/instructor/08-data-frames.html b/instructor/08-data-frames.html
index 073ac5c89..f7c0e6c55 100644
--- a/instructor/08-data-frames.html
+++ b/instructor/08-data-frames.html
@@ -388,7 +388,7 @@ <h2 class="accordion-header" id="flush-headingTwelve">
       </div>
       <hr></nav><main id="main-content" class="main-content"><div class="container lesson-content">
         <h1>Pandas DataFrames</h1>
-        <p> Last updated on 2023-06-05 | 
+        <p> Last updated on 2023-07-24 | 
         
         <a href="https://github.com/swcarpentry/python-novice-gapminder/edit/main/episodes/08-data-frames.md" class="external-link">Edit this page <i aria-hidden="true" data-feather="edit"></i></a></p>
         
@@ -673,7 +673,7 @@ <h3 class="accordion-header" id="headingInstructor1">
   Instructor Note
   </h3>
 </button>
-<div id="collapseInstructor1" class="accordion-collapse collapse" data-bs-parent="#accordionInstructor1" aria-labelledby="headingInstructor1">
+<div id="collapseInstructor1" class="accordion-collapse collapse" aria-labelledby="headingInstructor1" data-bs-parent="#accordionInstructor1">
 <div class="accordion-body">
 <p>Learners often struggle here, many may not work with financial data
 and concepts so they find the example concepts difficult to get their
@@ -784,7 +784,7 @@ <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"><
 </h3>
 <pre class="sourceCode python" tabindex="0"><code class="sourceCode python"><span id="cb25-1"><a href="#cb25-1" aria-hidden="true" tabindex="-1"></a><span class="im">import</span> pandas <span class="im">as</span> pd</span>
 <span id="cb25-2"><a href="#cb25-2" aria-hidden="true" tabindex="-1"></a></span>
-<span id="cb25-3"><a href="#cb25-3" aria-hidden="true" tabindex="-1"></a>df <span class="op">=</span> pd.read_csv(<span class="st">'data/gapminder_gdp_europe.csv'</span>, index_col<span class="op">=</span><span class="st">'country'</span>)</span></code></pre>
+<span id="cb25-3"><a href="#cb25-3" aria-hidden="true" tabindex="-1"></a>data_europe <span class="op">=</span> pd.read_csv(<span class="st">'data/gapminder_gdp_europe.csv'</span>, index_col<span class="op">=</span><span class="st">'country'</span>)</span></code></pre>
 </div>
 <p>Write an expression to find the Per Capita GDP of Serbia in 2007.</p>
 </div>
@@ -797,14 +797,14 @@ <h4 class="accordion-header" id="headingSolution1">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
 <div class="accordion-body">
 <p>The selection can be done by using the labels for both the row
 (“Serbia”) and the column (“gdpPercap_2007”):</p>
 <div class="codewrapper sourceCode" id="cb26">
 <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode python" tabindex="0"><code class="sourceCode python"><span id="cb26-1"><a href="#cb26-1" aria-hidden="true" tabindex="-1"></a><span class="bu">print</span>(df.loc[<span class="st">'Serbia'</span>, <span class="st">'gdpPercap_2007'</span>])</span></code></pre>
+<pre class="sourceCode python" tabindex="0"><code class="sourceCode python"><span id="cb26-1"><a href="#cb26-1" aria-hidden="true" tabindex="-1"></a><span class="bu">print</span>(data_europe.loc[<span class="st">'Serbia'</span>, <span class="st">'gdpPercap_2007'</span>])</span></code></pre>
 </div>
 <p>The output is</p>
 <div class="codewrapper">
@@ -830,8 +830,8 @@ <h3 class="callout-title">Extent of Slicing<a class="anchor" aria-label="anchor"
 </ol><div class="codewrapper sourceCode" id="cb28">
 <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode python" tabindex="0"><code class="sourceCode python"><span id="cb28-1"><a href="#cb28-1" aria-hidden="true" tabindex="-1"></a><span class="bu">print</span>(df.iloc[<span class="dv">0</span>:<span class="dv">2</span>, <span class="dv">0</span>:<span class="dv">2</span>])</span>
-<span id="cb28-2"><a href="#cb28-2" aria-hidden="true" tabindex="-1"></a><span class="bu">print</span>(df.loc[<span class="st">'Albania'</span>:<span class="st">'Belgium'</span>, <span class="st">'gdpPercap_1952'</span>:<span class="st">'gdpPercap_1962'</span>])</span></code></pre>
+<pre class="sourceCode python" tabindex="0"><code class="sourceCode python"><span id="cb28-1"><a href="#cb28-1" aria-hidden="true" tabindex="-1"></a><span class="bu">print</span>(data_europe.iloc[<span class="dv">0</span>:<span class="dv">2</span>, <span class="dv">0</span>:<span class="dv">2</span>])</span>
+<span id="cb28-2"><a href="#cb28-2" aria-hidden="true" tabindex="-1"></a><span class="bu">print</span>(data_europe.loc[<span class="st">'Albania'</span>:<span class="st">'Belgium'</span>, <span class="st">'gdpPercap_1952'</span>:<span class="st">'gdpPercap_1962'</span>])</span></code></pre>
 </div>
 </div>
 </div>
@@ -843,7 +843,7 @@ <h4 class="accordion-header" id="headingSolution2">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
 <div class="accordion-body">
 <p>No, they do not produce the same output! The output of the first
 statement is:</p>
@@ -904,7 +904,7 @@ <h4 class="accordion-header" id="headingSolution3">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
 <div class="accordion-body">
 <p>Let’s go through this piece of code line by line.</p>
 <div class="codewrapper sourceCode" id="cb32">
@@ -988,7 +988,7 @@ <h4 class="accordion-header" id="headingSolution4">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution4" class="accordion-collapse collapse" data-bs-parent="#accordionSolution4" aria-labelledby="headingSolution4">
+<div id="collapseSolution4" class="accordion-collapse collapse" aria-labelledby="headingSolution4" data-bs-parent="#accordionSolution4">
 <div class="accordion-body">
 <p>For each column in <code>data</code>, <code>idxmin</code> will return
 the index value corresponding to each column’s minimum;
@@ -1026,7 +1026,7 @@ <h4 class="accordion-header" id="headingSolution5">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution5" class="accordion-collapse collapse" data-bs-parent="#accordionSolution5" aria-labelledby="headingSolution5">
+<div id="collapseSolution5" class="accordion-collapse collapse" aria-labelledby="headingSolution5" data-bs-parent="#accordionSolution5">
 <div class="accordion-body">
 <p>1:</p>
 <div class="codewrapper sourceCode" id="cb38">
@@ -1103,7 +1103,7 @@ <h4 class="accordion-header" id="headingSolution6">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution6" class="accordion-collapse collapse" data-bs-parent="#accordionSolution6" aria-labelledby="headingSolution6">
+<div id="collapseSolution6" class="accordion-collapse collapse" aria-labelledby="headingSolution6" data-bs-parent="#accordionSolution6">
 <div class="accordion-body">
 <p>1. Access a single column:</p>
 <div class="codewrapper sourceCode" id="cb42">
@@ -1292,7 +1292,7 @@ <h4 class="accordion-header" id="headingSolution7">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution7" class="accordion-collapse collapse" data-bs-parent="#accordionSolution7" aria-labelledby="headingSolution7">
+<div id="collapseSolution7" class="accordion-collapse collapse" aria-labelledby="headingSolution7" data-bs-parent="#accordionSolution7">
 <div class="accordion-body">
 <p>Among many choices, <code>dir()</code> lists the
 <code>median()</code> function as a possibility. Thus,</p>
@@ -1392,8 +1392,8 @@ <h3 class="callout-title">Keypoints<a class="anchor" aria-label="anchor" href="#
   "url": "https://swcarpentry.github.io/python-novice-gapminder/instructor/08-data-frames.html",
   "identifier": "https://swcarpentry.github.io/python-novice-gapminder/instructor/08-data-frames.html",
   "dateCreated": "2016-01-07",
-  "dateModified": "2023-06-05",
-  "datePublished": "2023-07-18"
+  "dateModified": "2023-07-24",
+  "datePublished": "2023-07-24"
 }
 
   </script><script>
diff --git a/instructor/09-plotting.html b/instructor/09-plotting.html
index 18cd51f56..ee06ccdaa 100644
--- a/instructor/09-plotting.html
+++ b/instructor/09-plotting.html
@@ -914,7 +914,7 @@ <h3 class="callout-title">Keypoints<a class="anchor" aria-label="anchor" href="#
   "identifier": "https://swcarpentry.github.io/python-novice-gapminder/instructor/09-plotting.html",
   "dateCreated": "2016-01-07",
   "dateModified": "2023-06-08",
-  "datePublished": "2023-07-18"
+  "datePublished": "2023-07-24"
 }
 
   </script><script>
diff --git a/instructor/10-lunch.html b/instructor/10-lunch.html
index bffe66074..706d2c3d4 100644
--- a/instructor/10-lunch.html
+++ b/instructor/10-lunch.html
@@ -444,7 +444,7 @@ <h1>Lunch</h1>
   "identifier": "https://swcarpentry.github.io/python-novice-gapminder/instructor/10-lunch.html",
   "dateCreated": "2016-01-07",
   "dateModified": "2023-05-02",
-  "datePublished": "2023-07-18"
+  "datePublished": "2023-07-24"
 }
 
   </script><script>
diff --git a/instructor/11-lists.html b/instructor/11-lists.html
index d745a10b8..bd0cccf3f 100644
--- a/instructor/11-lists.html
+++ b/instructor/11-lists.html
@@ -1092,7 +1092,7 @@ <h3 class="callout-title">Keypoints<a class="anchor" aria-label="anchor" href="#
   "identifier": "https://swcarpentry.github.io/python-novice-gapminder/instructor/11-lists.html",
   "dateCreated": "2016-01-07",
   "dateModified": "2023-05-02",
-  "datePublished": "2023-07-18"
+  "datePublished": "2023-07-24"
 }
 
   </script><script>
diff --git a/instructor/12-for-loops.html b/instructor/12-for-loops.html
index 8b8c4dde2..529cb637a 100644
--- a/instructor/12-for-loops.html
+++ b/instructor/12-for-loops.html
@@ -1119,7 +1119,7 @@ <h3 class="callout-title">Keypoints<a class="anchor" aria-label="anchor" href="#
   "identifier": "https://swcarpentry.github.io/python-novice-gapminder/instructor/12-for-loops.html",
   "dateCreated": "2016-01-07",
   "dateModified": "2023-05-02",
-  "datePublished": "2023-07-18"
+  "datePublished": "2023-07-24"
 }
 
   </script><script>
diff --git a/instructor/13-conditionals.html b/instructor/13-conditionals.html
index 9af329b62..e2e7ca049 100644
--- a/instructor/13-conditionals.html
+++ b/instructor/13-conditionals.html
@@ -745,7 +745,7 @@ <h4 class="accordion-header" id="headingSolution1">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
 <div class="accordion-body">
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -794,7 +794,7 @@ <h4 class="accordion-header" id="headingSolution2">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
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@@ -842,7 +842,7 @@ <h4 class="accordion-header" id="headingSolution3">
   Show me the solution
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 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
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@@ -893,7 +893,7 @@ <h4 class="accordion-header" id="headingSolution4">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution4" class="accordion-collapse collapse" data-bs-parent="#accordionSolution4" aria-labelledby="headingSolution4">
+<div id="collapseSolution4" class="accordion-collapse collapse" aria-labelledby="headingSolution4" data-bs-parent="#accordionSolution4">
 <div class="accordion-body">
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@@ -1019,7 +1019,7 @@ <h3 class="callout-title">Keypoints<a class="anchor" aria-label="anchor" href="#
   "identifier": "https://swcarpentry.github.io/python-novice-gapminder/instructor/13-conditionals.html",
   "dateCreated": "2016-01-07",
   "dateModified": "2023-05-02",
-  "datePublished": "2023-07-18"
+  "datePublished": "2023-07-24"
 }
 
   </script><script>
diff --git a/instructor/14-looping-data-sets.html b/instructor/14-looping-data-sets.html
index eff11a00b..0db05bd91 100644
--- a/instructor/14-looping-data-sets.html
+++ b/instructor/14-looping-data-sets.html
@@ -547,7 +547,7 @@ <h4 class="accordion-header" id="headingSolution1">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
 <div class="accordion-body">
 <p>1 is not matched by the glob.</p>
 </div>
@@ -588,7 +588,7 @@ <h4 class="accordion-header" id="headingSolution2">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
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@@ -631,7 +631,7 @@ <h4 class="accordion-header" id="headingSolution3">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
 <div class="accordion-body">
 <p>This solution builds a useful legend by using the <a href="https://docs.python.org/3/library/stdtypes.html#str.split" class="external-link">string
 <code>split</code> method</a> to extract the <code>region</code> from
@@ -764,7 +764,7 @@ <h3 class="callout-title">Keypoints<a class="anchor" aria-label="anchor" href="#
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+  "datePublished": "2023-07-24"
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diff --git a/instructor/15-coffee.html b/instructor/15-coffee.html
index 608dd550e..19032be70 100644
--- a/instructor/15-coffee.html
+++ b/instructor/15-coffee.html
@@ -456,7 +456,7 @@ <h1>Afternoon Coffee</h1>
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   "dateCreated": "2016-01-07",
   "dateModified": "2023-05-02",
-  "datePublished": "2023-07-18"
+  "datePublished": "2023-07-24"
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diff --git a/instructor/16-writing-functions.html b/instructor/16-writing-functions.html
index 8190973eb..ae3c343c4 100644
--- a/instructor/16-writing-functions.html
+++ b/instructor/16-writing-functions.html
@@ -384,7 +384,7 @@ <h2 class="accordion-header" id="flush-headingTwelve">
       </div>
       <hr></nav><main id="main-content" class="main-content"><div class="container lesson-content">
         <h1>Writing Functions</h1>
-        <p> Last updated on 2023-05-02 | 
+        <p> Last updated on 2023-07-24 | 
         
         <a href="https://github.com/swcarpentry/python-novice-gapminder/edit/main/episodes/16-writing-functions.md" class="external-link">Edit this page <i aria-hidden="true" data-feather="edit"></i></a></p>
         
@@ -1004,8 +1004,8 @@ <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"><
 </h3>
 <pre class="sourceCode python" tabindex="0"><code class="sourceCode python"><span id="cb35-1"><a href="#cb35-1" aria-hidden="true" tabindex="-1"></a><span class="im">import</span> pandas <span class="im">as</span> pd</span>
 <span id="cb35-2"><a href="#cb35-2" aria-hidden="true" tabindex="-1"></a></span>
-<span id="cb35-3"><a href="#cb35-3" aria-hidden="true" tabindex="-1"></a>df <span class="op">=</span> pd.read_csv(<span class="st">'data/gapminder_gdp_asia.csv'</span>, index_col<span class="op">=</span><span class="dv">0</span>)</span>
-<span id="cb35-4"><a href="#cb35-4" aria-hidden="true" tabindex="-1"></a>japan <span class="op">=</span> df.loc[<span class="st">'Japan'</span>]</span></code></pre>
+<span id="cb35-3"><a href="#cb35-3" aria-hidden="true" tabindex="-1"></a>data_asia <span class="op">=</span> pd.read_csv(<span class="st">'data/gapminder_gdp_asia.csv'</span>, index_col<span class="op">=</span><span class="dv">0</span>)</span>
+<span id="cb35-4"><a href="#cb35-4" aria-hidden="true" tabindex="-1"></a>japan <span class="op">=</span> data_asia.loc[<span class="st">'Japan'</span>]</span></code></pre>
 </div>
 <ol style="list-style-type: decimal"><li>Complete the statements below to obtain the average GDP for Japan
 across the years reported for the 1980s.</li>
@@ -1021,7 +1021,7 @@ <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"><
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 </h3>
 <pre class="sourceCode python" tabindex="0"><code class="sourceCode python"><span id="cb37-1"><a href="#cb37-1" aria-hidden="true" tabindex="-1"></a><span class="kw">def</span> avg_gdp_in_decade(country, continent, year):</span>
-<span id="cb37-2"><a href="#cb37-2" aria-hidden="true" tabindex="-1"></a>    df <span class="op">=</span> pd.read_csv(<span class="st">'data/gapminder_gdp_'</span><span class="op">+</span>___<span class="op">+</span><span class="st">'.csv'</span>,delimiter<span class="op">=</span><span class="st">','</span>,index_col<span class="op">=</span><span class="dv">0</span>)</span>
+<span id="cb37-2"><a href="#cb37-2" aria-hidden="true" tabindex="-1"></a>    data_countries <span class="op">=</span> pd.read_csv(<span class="st">'data/gapminder_gdp_'</span><span class="op">+</span>___<span class="op">+</span><span class="st">'.csv'</span>,delimiter<span class="op">=</span><span class="st">','</span>,index_col<span class="op">=</span><span class="dv">0</span>)</span>
 <span id="cb37-3"><a href="#cb37-3" aria-hidden="true" tabindex="-1"></a>    ____</span>
 <span id="cb37-4"><a href="#cb37-4" aria-hidden="true" tabindex="-1"></a>    ____</span>
 <span id="cb37-5"><a href="#cb37-5" aria-hidden="true" tabindex="-1"></a>    ____</span>
@@ -1058,8 +1058,8 @@ <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"><
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 <pre class="sourceCode python" tabindex="0"><code class="sourceCode python"><span id="cb39-1"><a href="#cb39-1" aria-hidden="true" tabindex="-1"></a><span class="kw">def</span> avg_gdp_in_decade(country, continent, year):</span>
-<span id="cb39-2"><a href="#cb39-2" aria-hidden="true" tabindex="-1"></a>    df <span class="op">=</span> pd.read_csv(<span class="st">'data/gapminder_gdp_'</span> <span class="op">+</span> continent <span class="op">+</span> <span class="st">'.csv'</span>, index_col<span class="op">=</span><span class="dv">0</span>)</span>
-<span id="cb39-3"><a href="#cb39-3" aria-hidden="true" tabindex="-1"></a>    c <span class="op">=</span> df.loc[country]</span>
+<span id="cb39-2"><a href="#cb39-2" aria-hidden="true" tabindex="-1"></a>    data_countries <span class="op">=</span> pd.read_csv(<span class="st">'data/gapminder_gdp_'</span> <span class="op">+</span> continent <span class="op">+</span> <span class="st">'.csv'</span>, index_col<span class="op">=</span><span class="dv">0</span>)</span>
+<span id="cb39-3"><a href="#cb39-3" aria-hidden="true" tabindex="-1"></a>    c <span class="op">=</span> data_countries.loc[country]</span>
 <span id="cb39-4"><a href="#cb39-4" aria-hidden="true" tabindex="-1"></a>    gdp_decade <span class="op">=</span> <span class="st">'gdpPercap_'</span> <span class="op">+</span> <span class="bu">str</span>(year <span class="op">//</span> <span class="dv">10</span>)</span>
 <span id="cb39-5"><a href="#cb39-5" aria-hidden="true" tabindex="-1"></a>    avg <span class="op">=</span> (c.loc[gdp_decade <span class="op">+</span> <span class="st">'2'</span>] <span class="op">+</span> c.loc[gdp_decade <span class="op">+</span> <span class="st">'7'</span>])<span class="op">/</span><span class="dv">2</span></span>
 <span id="cb39-6"><a href="#cb39-6" aria-hidden="true" tabindex="-1"></a>    <span class="cf">return</span> avg</span></code></pre>
@@ -1070,8 +1070,8 @@ <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"><
 <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
 <pre class="sourceCode python" tabindex="0"><code class="sourceCode python"><span id="cb40-1"><a href="#cb40-1" aria-hidden="true" tabindex="-1"></a><span class="kw">def</span> avg_gdp_in_decade(country, continent, year):</span>
-<span id="cb40-2"><a href="#cb40-2" aria-hidden="true" tabindex="-1"></a>    df <span class="op">=</span> pd.read_csv(<span class="st">'data/gapminder_gdp_'</span> <span class="op">+</span> continent <span class="op">+</span> <span class="st">'.csv'</span>, index_col<span class="op">=</span><span class="dv">0</span>)</span>
-<span id="cb40-3"><a href="#cb40-3" aria-hidden="true" tabindex="-1"></a>    c <span class="op">=</span> df.loc[country]</span>
+<span id="cb40-2"><a href="#cb40-2" aria-hidden="true" tabindex="-1"></a>    data_countries <span class="op">=</span> pd.read_csv(<span class="st">'data/gapminder_gdp_'</span> <span class="op">+</span> continent <span class="op">+</span> <span class="st">'.csv'</span>, index_col<span class="op">=</span><span class="dv">0</span>)</span>
+<span id="cb40-3"><a href="#cb40-3" aria-hidden="true" tabindex="-1"></a>    c <span class="op">=</span> data_countries.loc[country]</span>
 <span id="cb40-4"><a href="#cb40-4" aria-hidden="true" tabindex="-1"></a>    gdp_decade <span class="op">=</span> <span class="st">'gdpPercap_'</span> <span class="op">+</span> <span class="bu">str</span>(year <span class="op">//</span> <span class="dv">10</span>)</span>
 <span id="cb40-5"><a href="#cb40-5" aria-hidden="true" tabindex="-1"></a>    total <span class="op">=</span> <span class="fl">0.0</span></span>
 <span id="cb40-6"><a href="#cb40-6" aria-hidden="true" tabindex="-1"></a>    num_years <span class="op">=</span> <span class="dv">0</span></span>
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   "dateCreated": "2016-01-07",
-  "dateModified": "2023-05-02",
-  "datePublished": "2023-07-18"
+  "dateModified": "2023-07-24",
+  "datePublished": "2023-07-24"
 }
 
   </script><script>
diff --git a/instructor/17-scope.html b/instructor/17-scope.html
index 7114124ab..4320ac780 100644
--- a/instructor/17-scope.html
+++ b/instructor/17-scope.html
@@ -540,7 +540,7 @@ <h4 class="accordion-header" id="headingSolution1">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
 <div class="accordion-body">
 <ol style="list-style-type: decimal"><li>Three levels.</li>
 <li><code>errors_02.py</code></li>
@@ -624,7 +624,7 @@ <h3 class="callout-title">Keypoints<a class="anchor" aria-label="anchor" href="#
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   "dateModified": "2023-05-02",
-  "datePublished": "2023-07-18"
+  "datePublished": "2023-07-24"
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diff --git a/instructor/18-style.html b/instructor/18-style.html
index 9d3867597..de39033c6 100644
--- a/instructor/18-style.html
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@@ -589,7 +589,7 @@ <h4 class="accordion-header" id="headingSolution1">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
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 <div class="codewrapper sourceCode" id="cb7">
 <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -648,7 +648,7 @@ <h4 class="accordion-header" id="headingSolution2">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
 <div class="accordion-body">
 <p>Here’s one solution.</p>
 <div class="codewrapper sourceCode" id="cb9">
@@ -766,7 +766,7 @@ <h3 class="callout-title">Keypoints<a class="anchor" aria-label="anchor" href="#
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-  "datePublished": "2023-07-18"
+  "datePublished": "2023-07-24"
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diff --git a/instructor/19-wrap.html b/instructor/19-wrap.html
index 8b3e38bde..116cdb21e 100644
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   "dateCreated": "2016-01-07",
   "dateModified": "2023-05-02",
-  "datePublished": "2023-07-18"
+  "datePublished": "2023-07-24"
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diff --git a/instructor/20-feedback.html b/instructor/20-feedback.html
index 607a0e9a8..88b6b012d 100644
--- a/instructor/20-feedback.html
+++ b/instructor/20-feedback.html
@@ -474,7 +474,7 @@ <h3 class="callout-title">Keypoints<a class="anchor" aria-label="anchor" href="#
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   "dateCreated": "2016-01-07",
   "dateModified": "2023-05-02",
-  "datePublished": "2023-07-18"
+  "datePublished": "2023-07-24"
 }
 
   </script><script>
diff --git a/instructor/404.html b/instructor/404.html
index 66696fc88..4a516656c 100644
--- a/instructor/404.html
+++ b/instructor/404.html
@@ -416,8 +416,8 @@ <h1>Page not found</h1>
   "url": "https://swcarpentry.github.io/python-novice-gapminder/instructor/404.html",
   "identifier": "https://swcarpentry.github.io/python-novice-gapminder/instructor/404.html",
   "dateCreated": "2016-01-07",
-  "dateModified": "2023-07-18",
-  "datePublished": "2023-07-18"
+  "dateModified": "2023-07-24",
+  "datePublished": "2023-07-24"
 }
 
   </script><script>
diff --git a/instructor/CODE_OF_CONDUCT.html b/instructor/CODE_OF_CONDUCT.html
index ea26d4cac..9dffbc9a9 100644
--- a/instructor/CODE_OF_CONDUCT.html
+++ b/instructor/CODE_OF_CONDUCT.html
@@ -442,7 +442,7 @@ <h1>Contributor Code of Conduct</h1>
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   "dateCreated": "2016-01-07",
   "dateModified": "2023-05-02",
-  "datePublished": "2023-07-18"
+  "datePublished": "2023-07-24"
 }
 
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diff --git a/instructor/LICENSE.html b/instructor/LICENSE.html
index 5d92a0657..2e371c9a1 100644
--- a/instructor/LICENSE.html
+++ b/instructor/LICENSE.html
@@ -493,7 +493,7 @@ <h1>Licenses</h1>
   "identifier": "https://swcarpentry.github.io/python-novice-gapminder/instructor/LICENSE.html",
   "dateCreated": "2016-01-07",
   "dateModified": "2023-05-02",
-  "datePublished": "2023-07-18"
+  "datePublished": "2023-07-24"
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diff --git a/instructor/aio.html b/instructor/aio.html
index 52aaf7533..f3fb10c78 100644
--- a/instructor/aio.html
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@@ -827,7 +827,7 @@ <h4 class="accordion-header" id="headingSolution1">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
 <div class="accordion-body">
 <p>After creating the necessary tabs, you can drag one of the tabs to
 the center of a panel to move the tab to the panel; next you can
@@ -899,7 +899,7 @@ <h4 class="accordion-header" id="headingSolution2">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
 <div class="accordion-body">
 <p>Command mode has a grey border and Edit mode has a blue border. Use
 <kbd>Esc</kbd> and <kbd>Return</kbd> to switch between modes. You need
@@ -1090,7 +1090,7 @@ <h4 class="accordion-header" id="headingSolution3">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
 <div class="accordion-body">
 <p>This challenge integrates both the numbered list and bullet list.
 Note that the bullet list is indented 2 spaces so that it is inline with
@@ -1133,7 +1133,7 @@ <h4 class="accordion-header" id="headingSolution4">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution4" class="accordion-collapse collapse" aria-labelledby="headingSolution4" data-bs-parent="#accordionSolution4">
+<div id="collapseSolution4" class="accordion-collapse collapse" data-bs-parent="#accordionSolution4" aria-labelledby="headingSolution4">
 <div class="accordion-body">
 <p>Python returns the output of the last calculation.</p>
 <div class="codewrapper sourceCode" id="cb12">
@@ -1178,7 +1178,7 @@ <h4 class="accordion-header" id="headingSolution5">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution5" class="accordion-collapse collapse" aria-labelledby="headingSolution5" data-bs-parent="#accordionSolution5">
+<div id="collapseSolution5" class="accordion-collapse collapse" data-bs-parent="#accordionSolution5" aria-labelledby="headingSolution5">
 <div class="accordion-body">
 <p>The Python code gets treated like Markdown text. The lines appear as
 if they are part of one contiguous paragraph. This could be useful to
@@ -1218,7 +1218,7 @@ <h4 class="accordion-header" id="headingSolution6">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution6" class="accordion-collapse collapse" aria-labelledby="headingSolution6" data-bs-parent="#accordionSolution6">
+<div id="collapseSolution6" class="accordion-collapse collapse" data-bs-parent="#accordionSolution6" aria-labelledby="headingSolution6">
 <div class="accordion-body">
 <p>The notebook shows the equation as it would be rendered from LaTeX
 equation syntax. The dollar sign, <code>$</code>, is used to tell
@@ -1601,7 +1601,7 @@ <h4 class="accordion-header" id="headingSolution1">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
 <div class="accordion-body">
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1648,7 +1648,7 @@ <h4 class="accordion-header" id="headingSolution2">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
 <div class="accordion-body">
 <div class="codewrapper sourceCode" id="cb20">
 <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1690,7 +1690,7 @@ <h4 class="accordion-header" id="headingSolution3">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
 <div class="accordion-body">
 <p>Numbers are not strings or sequences and Python will raise an error
 if you try to perform an index operation on a number. In the <a href="03-types-conversion.html">next lesson on types and type
@@ -1750,7 +1750,7 @@ <h4 class="accordion-header" id="headingSolution4">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution4" class="accordion-collapse collapse" data-bs-parent="#accordionSolution4" aria-labelledby="headingSolution4">
+<div id="collapseSolution4" class="accordion-collapse collapse" aria-labelledby="headingSolution4" data-bs-parent="#accordionSolution4">
 <div class="accordion-body">
 <p><code>minutes</code> is better because <code>min</code> might mean
 something like “minimum” (and actually is an existing built-in function
@@ -1784,7 +1784,7 @@ <h4 class="accordion-header" id="headingSolution5">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution5" class="accordion-collapse collapse" data-bs-parent="#accordionSolution5" aria-labelledby="headingSolution5">
+<div id="collapseSolution5" class="accordion-collapse collapse" aria-labelledby="headingSolution5" data-bs-parent="#accordionSolution5">
 <div class="accordion-body">
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1836,7 +1836,7 @@ <h4 class="accordion-header" id="headingSolution6">
   Solutions
   </h4>
 </button>
-<div id="collapseSolution6" class="accordion-collapse collapse" data-bs-parent="#accordionSolution6" aria-labelledby="headingSolution6">
+<div id="collapseSolution6" class="accordion-collapse collapse" aria-labelledby="headingSolution6" data-bs-parent="#accordionSolution6">
 <div class="accordion-body">
 <ol style="list-style-type: decimal">
 <li>
@@ -2994,7 +2994,7 @@ <h4 class="accordion-header" id="headingSolution1">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
 <div class="accordion-body">
 <ol style="list-style-type: decimal">
 <li>Order of operations:</li>
@@ -3044,7 +3044,7 @@ <h4 class="accordion-header" id="headingSolution2">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
 <div class="accordion-body">
 <div class="codewrapper sourceCode" id="cb30">
 <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -3112,7 +3112,7 @@ <h4 class="accordion-header" id="headingSolution3">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
 <div class="accordion-body">
 <p><code>max</code> and <code>min</code> return TypeErrors in this case
 because the correct number of parameters was not supplied. If it just
@@ -3145,7 +3145,7 @@ <h4 class="accordion-header" id="headingSolution4">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution4" class="accordion-collapse collapse" aria-labelledby="headingSolution4" data-bs-parent="#accordionSolution4">
+<div id="collapseSolution4" class="accordion-collapse collapse" data-bs-parent="#accordionSolution4" aria-labelledby="headingSolution4">
 <div class="accordion-body">
 <p><code>name[len(name) - 1]</code></p>
 </div>
@@ -3448,7 +3448,7 @@ <h4 class="accordion-header" id="headingSolution1">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
 <div class="accordion-body">
 <ol style="list-style-type: decimal">
 <li><p>Using <code>help(math)</code> we see that we’ve got
@@ -3498,7 +3498,7 @@ <h4 class="accordion-header" id="headingSolution2">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
 <div class="accordion-body">
 <p>The <a href="https://docs.python.org/3/library/random.html" class="external-link">random
 module</a> seems like it could help.</p>
@@ -3580,7 +3580,7 @@ <h4 class="accordion-header" id="headingSolution3">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
 <div class="accordion-body">
 <div class="codewrapper sourceCode" id="cb15">
 <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -3622,7 +3622,7 @@ <h4 class="accordion-header" id="headingSolution4">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution4" class="accordion-collapse collapse" aria-labelledby="headingSolution4" data-bs-parent="#accordionSolution4">
+<div id="collapseSolution4" class="accordion-collapse collapse" data-bs-parent="#accordionSolution4" aria-labelledby="headingSolution4">
 <div class="accordion-body">
 <p>Importing the math module (<code>import math</code>)</p>
 </div>
@@ -3661,7 +3661,7 @@ <h4 class="accordion-header" id="headingSolution5">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution5" class="accordion-collapse collapse" aria-labelledby="headingSolution5" data-bs-parent="#accordionSolution5">
+<div id="collapseSolution5" class="accordion-collapse collapse" data-bs-parent="#accordionSolution5" aria-labelledby="headingSolution5">
 <div class="accordion-body">
 <div class="codewrapper sourceCode" id="cb18">
 <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -3721,7 +3721,7 @@ <h4 class="accordion-header" id="headingSolution6">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution6" class="accordion-collapse collapse" aria-labelledby="headingSolution6" data-bs-parent="#accordionSolution6">
+<div id="collapseSolution6" class="accordion-collapse collapse" data-bs-parent="#accordionSolution6" aria-labelledby="headingSolution6">
 <div class="accordion-body">
 <ol style="list-style-type: decimal">
 <li>Library calls 1 and 4. In order to directly refer to
@@ -3783,7 +3783,7 @@ <h4 class="accordion-header" id="headingSolution7">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution7" class="accordion-collapse collapse" aria-labelledby="headingSolution7" data-bs-parent="#accordionSolution7">
+<div id="collapseSolution7" class="accordion-collapse collapse" data-bs-parent="#accordionSolution7" aria-labelledby="headingSolution7">
 <div class="accordion-body">
 <div class="codewrapper sourceCode" id="cb21">
 <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -3832,7 +3832,7 @@ <h4 class="accordion-header" id="headingSolution8">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution8" class="accordion-collapse collapse" aria-labelledby="headingSolution8" data-bs-parent="#accordionSolution8">
+<div id="collapseSolution8" class="accordion-collapse collapse" data-bs-parent="#accordionSolution8" aria-labelledby="headingSolution8">
 <div class="accordion-body">
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -4481,7 +4481,7 @@ <h3 class="callout-title">Keypoints<a class="anchor" aria-label="anchor" href="#
 </div>
 </section></section><section id="aio-08-data-frames"><p>Content from <a href="08-data-frames.html">Pandas DataFrames</a></p>
 <hr>
-<p> Last updated on 2023-06-05 | 
+<p> Last updated on 2023-07-24 | 
         
         <a href="https://github.com/swcarpentry/python-novice-gapminder/edit/main/episodes/08-data-frames.md" class="external-link">Edit this page <i aria-hidden="true" data-feather="edit"></i></a></p>
 <p>Estimated time <i aria-hidden="true" data-feather="clock"></i> 30 minutes </p>
@@ -4790,7 +4790,7 @@ <h3 class="accordion-header" id="headingInstructor1">
   Instructor Note
   </h3>
 </button>
-<div id="collapseInstructor1" class="accordion-collapse collapse" data-bs-parent="#accordionInstructor1" aria-labelledby="headingInstructor1">
+<div id="collapseInstructor1" class="accordion-collapse collapse" aria-labelledby="headingInstructor1" data-bs-parent="#accordionInstructor1">
 <div class="accordion-body">
 <p>Learners often struggle here, many may not work with financial data
 and concepts so they find the example concepts difficult to get their
@@ -4903,7 +4903,7 @@ <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"><
 </h3>
 <pre class="sourceCode python" tabindex="0"><code class="sourceCode python"><span id="cb25-1"><a href="#cb25-1" aria-hidden="true" tabindex="-1"></a><span class="im">import</span> pandas <span class="im">as</span> pd</span>
 <span id="cb25-2"><a href="#cb25-2" aria-hidden="true" tabindex="-1"></a></span>
-<span id="cb25-3"><a href="#cb25-3" aria-hidden="true" tabindex="-1"></a>df <span class="op">=</span> pd.read_csv(<span class="st">'data/gapminder_gdp_europe.csv'</span>, index_col<span class="op">=</span><span class="st">'country'</span>)</span></code></pre>
+<span id="cb25-3"><a href="#cb25-3" aria-hidden="true" tabindex="-1"></a>data_europe <span class="op">=</span> pd.read_csv(<span class="st">'data/gapminder_gdp_europe.csv'</span>, index_col<span class="op">=</span><span class="st">'country'</span>)</span></code></pre>
 </div>
 <p>Write an expression to find the Per Capita GDP of Serbia in 2007.</p>
 </div>
@@ -4916,14 +4916,14 @@ <h4 class="accordion-header" id="headingSolution1">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
 <div class="accordion-body">
 <p>The selection can be done by using the labels for both the row
 (“Serbia”) and the column (“gdpPercap_2007”):</p>
 <div class="codewrapper sourceCode" id="cb26">
 <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode python" tabindex="0"><code class="sourceCode python"><span id="cb26-1"><a href="#cb26-1" aria-hidden="true" tabindex="-1"></a><span class="bu">print</span>(df.loc[<span class="st">'Serbia'</span>, <span class="st">'gdpPercap_2007'</span>])</span></code></pre>
+<pre class="sourceCode python" tabindex="0"><code class="sourceCode python"><span id="cb26-1"><a href="#cb26-1" aria-hidden="true" tabindex="-1"></a><span class="bu">print</span>(data_europe.loc[<span class="st">'Serbia'</span>, <span class="st">'gdpPercap_2007'</span>])</span></code></pre>
 </div>
 <p>The output is</p>
 <div class="codewrapper">
@@ -4951,8 +4951,8 @@ <h3 class="callout-title">Extent of Slicing<a class="anchor" aria-label="anchor"
 <div class="codewrapper sourceCode" id="cb28">
 <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode python" tabindex="0"><code class="sourceCode python"><span id="cb28-1"><a href="#cb28-1" aria-hidden="true" tabindex="-1"></a><span class="bu">print</span>(df.iloc[<span class="dv">0</span>:<span class="dv">2</span>, <span class="dv">0</span>:<span class="dv">2</span>])</span>
-<span id="cb28-2"><a href="#cb28-2" aria-hidden="true" tabindex="-1"></a><span class="bu">print</span>(df.loc[<span class="st">'Albania'</span>:<span class="st">'Belgium'</span>, <span class="st">'gdpPercap_1952'</span>:<span class="st">'gdpPercap_1962'</span>])</span></code></pre>
+<pre class="sourceCode python" tabindex="0"><code class="sourceCode python"><span id="cb28-1"><a href="#cb28-1" aria-hidden="true" tabindex="-1"></a><span class="bu">print</span>(data_europe.iloc[<span class="dv">0</span>:<span class="dv">2</span>, <span class="dv">0</span>:<span class="dv">2</span>])</span>
+<span id="cb28-2"><a href="#cb28-2" aria-hidden="true" tabindex="-1"></a><span class="bu">print</span>(data_europe.loc[<span class="st">'Albania'</span>:<span class="st">'Belgium'</span>, <span class="st">'gdpPercap_1952'</span>:<span class="st">'gdpPercap_1962'</span>])</span></code></pre>
 </div>
 </div>
 </div>
@@ -4964,7 +4964,7 @@ <h4 class="accordion-header" id="headingSolution2">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
 <div class="accordion-body">
 <p>No, they do not produce the same output! The output of the first
 statement is:</p>
@@ -5025,7 +5025,7 @@ <h4 class="accordion-header" id="headingSolution3">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
 <div class="accordion-body">
 <p>Let’s go through this piece of code line by line.</p>
 <div class="codewrapper sourceCode" id="cb32">
@@ -5109,7 +5109,7 @@ <h4 class="accordion-header" id="headingSolution4">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution4" class="accordion-collapse collapse" data-bs-parent="#accordionSolution4" aria-labelledby="headingSolution4">
+<div id="collapseSolution4" class="accordion-collapse collapse" aria-labelledby="headingSolution4" data-bs-parent="#accordionSolution4">
 <div class="accordion-body">
 <p>For each column in <code>data</code>, <code>idxmin</code> will return
 the index value corresponding to each column’s minimum;
@@ -5149,7 +5149,7 @@ <h4 class="accordion-header" id="headingSolution5">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution5" class="accordion-collapse collapse" data-bs-parent="#accordionSolution5" aria-labelledby="headingSolution5">
+<div id="collapseSolution5" class="accordion-collapse collapse" aria-labelledby="headingSolution5" data-bs-parent="#accordionSolution5">
 <div class="accordion-body">
 <p>1:</p>
 <div class="codewrapper sourceCode" id="cb38">
@@ -5228,7 +5228,7 @@ <h4 class="accordion-header" id="headingSolution6">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution6" class="accordion-collapse collapse" data-bs-parent="#accordionSolution6" aria-labelledby="headingSolution6">
+<div id="collapseSolution6" class="accordion-collapse collapse" aria-labelledby="headingSolution6" data-bs-parent="#accordionSolution6">
 <div class="accordion-body">
 <p>1. Access a single column:</p>
 <div class="codewrapper sourceCode" id="cb42">
@@ -5417,7 +5417,7 @@ <h4 class="accordion-header" id="headingSolution7">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution7" class="accordion-collapse collapse" data-bs-parent="#accordionSolution7" aria-labelledby="headingSolution7">
+<div id="collapseSolution7" class="accordion-collapse collapse" aria-labelledby="headingSolution7" data-bs-parent="#accordionSolution7">
 <div class="accordion-body">
 <p>Among many choices, <code>dir()</code> lists the
 <code>median()</code> function as a possibility. Thus,</p>
@@ -7839,7 +7839,7 @@ <h4 class="accordion-header" id="headingSolution1">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
 <div class="accordion-body">
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -7888,7 +7888,7 @@ <h4 class="accordion-header" id="headingSolution2">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
 <div class="accordion-body">
 <div class="codewrapper sourceCode" id="cb22">
 <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -7936,7 +7936,7 @@ <h4 class="accordion-header" id="headingSolution3">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
 <div class="accordion-body">
 <div class="codewrapper sourceCode" id="cb24">
 <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -7987,7 +7987,7 @@ <h4 class="accordion-header" id="headingSolution4">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution4" class="accordion-collapse collapse" data-bs-parent="#accordionSolution4" aria-labelledby="headingSolution4">
+<div id="collapseSolution4" class="accordion-collapse collapse" aria-labelledby="headingSolution4" data-bs-parent="#accordionSolution4">
 <div class="accordion-body">
 <div class="codewrapper sourceCode" id="cb26">
 <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -8241,7 +8241,7 @@ <h4 class="accordion-header" id="headingSolution1">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
 <div class="accordion-body">
 <p>1 is not matched by the glob.</p>
 </div>
@@ -8282,7 +8282,7 @@ <h4 class="accordion-header" id="headingSolution2">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
 <div class="accordion-body">
 <div class="codewrapper sourceCode" id="cb10">
 <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -8325,7 +8325,7 @@ <h4 class="accordion-header" id="headingSolution3">
   Show me the solution
   </h4>
 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
 <div class="accordion-body">
 <p>This solution builds a useful legend by using the <a href="https://docs.python.org/3/library/stdtypes.html#str.split" class="external-link">string
 <code>split</code> method</a> to extract the <code>region</code> from
@@ -8432,7 +8432,7 @@ <h3 class="callout-title">Keypoints<a class="anchor" aria-label="anchor" href="#
 definition?</li>
 </ul></section></section><section id="aio-16-writing-functions"><p>Content from <a href="16-writing-functions.html">Writing Functions</a></p>
 <hr>
-<p> Last updated on 2023-05-02 | 
+<p> Last updated on 2023-07-24 | 
         
         <a href="https://github.com/swcarpentry/python-novice-gapminder/edit/main/episodes/16-writing-functions.md" class="external-link">Edit this page <i aria-hidden="true" data-feather="edit"></i></a></p>
 <p>Estimated time <i aria-hidden="true" data-feather="clock"></i> 25 minutes </p>
@@ -9098,8 +9098,8 @@ <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"><
 </h3>
 <pre class="sourceCode python" tabindex="0"><code class="sourceCode python"><span id="cb35-1"><a href="#cb35-1" aria-hidden="true" tabindex="-1"></a><span class="im">import</span> pandas <span class="im">as</span> pd</span>
 <span id="cb35-2"><a href="#cb35-2" aria-hidden="true" tabindex="-1"></a></span>
-<span id="cb35-3"><a href="#cb35-3" aria-hidden="true" tabindex="-1"></a>df <span class="op">=</span> pd.read_csv(<span class="st">'data/gapminder_gdp_asia.csv'</span>, index_col<span class="op">=</span><span class="dv">0</span>)</span>
-<span id="cb35-4"><a href="#cb35-4" aria-hidden="true" tabindex="-1"></a>japan <span class="op">=</span> df.loc[<span class="st">'Japan'</span>]</span></code></pre>
+<span id="cb35-3"><a href="#cb35-3" aria-hidden="true" tabindex="-1"></a>data_asia <span class="op">=</span> pd.read_csv(<span class="st">'data/gapminder_gdp_asia.csv'</span>, index_col<span class="op">=</span><span class="dv">0</span>)</span>
+<span id="cb35-4"><a href="#cb35-4" aria-hidden="true" tabindex="-1"></a>japan <span class="op">=</span> data_asia.loc[<span class="st">'Japan'</span>]</span></code></pre>
 </div>
 <ol style="list-style-type: decimal">
 <li>Complete the statements below to obtain the average GDP for Japan
@@ -9119,7 +9119,7 @@ <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"><
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 <pre class="sourceCode python" tabindex="0"><code class="sourceCode python"><span id="cb37-1"><a href="#cb37-1" aria-hidden="true" tabindex="-1"></a><span class="kw">def</span> avg_gdp_in_decade(country, continent, year):</span>
-<span id="cb37-2"><a href="#cb37-2" aria-hidden="true" tabindex="-1"></a>    df <span class="op">=</span> pd.read_csv(<span class="st">'data/gapminder_gdp_'</span><span class="op">+</span>___<span class="op">+</span><span class="st">'.csv'</span>,delimiter<span class="op">=</span><span class="st">','</span>,index_col<span class="op">=</span><span class="dv">0</span>)</span>
+<span id="cb37-2"><a href="#cb37-2" aria-hidden="true" tabindex="-1"></a>    data_countries <span class="op">=</span> pd.read_csv(<span class="st">'data/gapminder_gdp_'</span><span class="op">+</span>___<span class="op">+</span><span class="st">'.csv'</span>,delimiter<span class="op">=</span><span class="st">','</span>,index_col<span class="op">=</span><span class="dv">0</span>)</span>
 <span id="cb37-3"><a href="#cb37-3" aria-hidden="true" tabindex="-1"></a>    ____</span>
 <span id="cb37-4"><a href="#cb37-4" aria-hidden="true" tabindex="-1"></a>    ____</span>
 <span id="cb37-5"><a href="#cb37-5" aria-hidden="true" tabindex="-1"></a>    ____</span>
@@ -9162,8 +9162,8 @@ <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"><
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 <pre class="sourceCode python" tabindex="0"><code class="sourceCode python"><span id="cb39-1"><a href="#cb39-1" aria-hidden="true" tabindex="-1"></a><span class="kw">def</span> avg_gdp_in_decade(country, continent, year):</span>
-<span id="cb39-2"><a href="#cb39-2" aria-hidden="true" tabindex="-1"></a>    df <span class="op">=</span> pd.read_csv(<span class="st">'data/gapminder_gdp_'</span> <span class="op">+</span> continent <span class="op">+</span> <span class="st">'.csv'</span>, index_col<span class="op">=</span><span class="dv">0</span>)</span>
-<span id="cb39-3"><a href="#cb39-3" aria-hidden="true" tabindex="-1"></a>    c <span class="op">=</span> df.loc[country]</span>
+<span id="cb39-2"><a href="#cb39-2" aria-hidden="true" tabindex="-1"></a>    data_countries <span class="op">=</span> pd.read_csv(<span class="st">'data/gapminder_gdp_'</span> <span class="op">+</span> continent <span class="op">+</span> <span class="st">'.csv'</span>, index_col<span class="op">=</span><span class="dv">0</span>)</span>
+<span id="cb39-3"><a href="#cb39-3" aria-hidden="true" tabindex="-1"></a>    c <span class="op">=</span> data_countries.loc[country]</span>
 <span id="cb39-4"><a href="#cb39-4" aria-hidden="true" tabindex="-1"></a>    gdp_decade <span class="op">=</span> <span class="st">'gdpPercap_'</span> <span class="op">+</span> <span class="bu">str</span>(year <span class="op">//</span> <span class="dv">10</span>)</span>
 <span id="cb39-5"><a href="#cb39-5" aria-hidden="true" tabindex="-1"></a>    avg <span class="op">=</span> (c.loc[gdp_decade <span class="op">+</span> <span class="st">'2'</span>] <span class="op">+</span> c.loc[gdp_decade <span class="op">+</span> <span class="st">'7'</span>])<span class="op">/</span><span class="dv">2</span></span>
 <span id="cb39-6"><a href="#cb39-6" aria-hidden="true" tabindex="-1"></a>    <span class="cf">return</span> avg</span></code></pre>
@@ -9176,8 +9176,8 @@ <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"><
 <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
 <pre class="sourceCode python" tabindex="0"><code class="sourceCode python"><span id="cb40-1"><a href="#cb40-1" aria-hidden="true" tabindex="-1"></a><span class="kw">def</span> avg_gdp_in_decade(country, continent, year):</span>
-<span id="cb40-2"><a href="#cb40-2" aria-hidden="true" tabindex="-1"></a>    df <span class="op">=</span> pd.read_csv(<span class="st">'data/gapminder_gdp_'</span> <span class="op">+</span> continent <span class="op">+</span> <span class="st">'.csv'</span>, index_col<span class="op">=</span><span class="dv">0</span>)</span>
-<span id="cb40-3"><a href="#cb40-3" aria-hidden="true" tabindex="-1"></a>    c <span class="op">=</span> df.loc[country]</span>
+<span id="cb40-2"><a href="#cb40-2" aria-hidden="true" tabindex="-1"></a>    data_countries <span class="op">=</span> pd.read_csv(<span class="st">'data/gapminder_gdp_'</span> <span class="op">+</span> continent <span class="op">+</span> <span class="st">'.csv'</span>, index_col<span class="op">=</span><span class="dv">0</span>)</span>
+<span id="cb40-3"><a href="#cb40-3" aria-hidden="true" tabindex="-1"></a>    c <span class="op">=</span> data_countries.loc[country]</span>
 <span id="cb40-4"><a href="#cb40-4" aria-hidden="true" tabindex="-1"></a>    gdp_decade <span class="op">=</span> <span class="st">'gdpPercap_'</span> <span class="op">+</span> <span class="bu">str</span>(year <span class="op">//</span> <span class="dv">10</span>)</span>
 <span id="cb40-5"><a href="#cb40-5" aria-hidden="true" tabindex="-1"></a>    total <span class="op">=</span> <span class="fl">0.0</span></span>
 <span id="cb40-6"><a href="#cb40-6" aria-hidden="true" tabindex="-1"></a>    num_years <span class="op">=</span> <span class="dv">0</span></span>
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-<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
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 <ol style="list-style-type: decimal">
 <li>Three levels.</li>
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 <p>Here’s one solution.</p>
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index 9e1979522..460d284f8 100644
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   "dateCreated": "2016-01-07",
   "dateModified": "2023-05-02",
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index bb223ebba..c9badcd37 100644
--- a/instructor/images.html
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@@ -607,8 +607,8 @@ <h3 id="09-plotting-figure-12">Figure 12</h3>
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   "identifier": "https://swcarpentry.github.io/python-novice-gapminder/instructor/images.html",
   "dateCreated": "2016-01-07",
-  "dateModified": "2023-07-18",
-  "datePublished": "2023-07-18"
+  "dateModified": "2023-07-24",
+  "datePublished": "2023-07-24"
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diff --git a/instructor/index.html b/instructor/index.html
index 8c0231835..c7652d510 100644
--- a/instructor/index.html
+++ b/instructor/index.html
@@ -651,8 +651,8 @@ <h3 class="callout-title">Prerequisites<a class="anchor" aria-label="anchor" hre
   "url": "https://swcarpentry.github.io/python-novice-gapminder/instructor/index.html",
   "identifier": "https://swcarpentry.github.io/python-novice-gapminder/instructor/index.html",
   "dateCreated": "2016-01-07",
-  "dateModified": "2023-07-18",
-  "datePublished": "2023-07-18"
+  "dateModified": "2023-07-24",
+  "datePublished": "2023-07-24"
 }
 
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diff --git a/instructor/instructor-notes.html b/instructor/instructor-notes.html
index 9741b1dee..1441c83a4 100644
--- a/instructor/instructor-notes.html
+++ b/instructor/instructor-notes.html
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   "url": "https://swcarpentry.github.io/python-novice-gapminder/instructor/instructor-notes.html",
   "identifier": "https://swcarpentry.github.io/python-novice-gapminder/instructor/instructor-notes.html",
   "dateCreated": "2016-01-07",
-  "dateModified": "2023-07-18",
-  "datePublished": "2023-07-18"
+  "dateModified": "2023-07-24",
+  "datePublished": "2023-07-24"
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diff --git a/instructor/key-points.html b/instructor/key-points.html
index d543fb0fc..da52dbac3 100644
--- a/instructor/key-points.html
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   "dateCreated": "2016-01-07",
-  "dateModified": "2023-07-18",
-  "datePublished": "2023-07-18"
+  "dateModified": "2023-07-24",
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diff --git a/instructor/profiles.html b/instructor/profiles.html
index dc38c1423..214550c45 100644
--- a/instructor/profiles.html
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@@ -403,8 +403,8 @@ <h1>Learner Profiles</h1>
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   "identifier": "https://swcarpentry.github.io/python-novice-gapminder/instructor/profiles.html",
   "dateCreated": "2016-01-07",
-  "dateModified": "2023-07-18",
-  "datePublished": "2023-07-18"
+  "dateModified": "2023-07-24",
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diff --git a/instructor/reference.html b/instructor/reference.html
index b99fa921c..b267af7be 100644
--- a/instructor/reference.html
+++ b/instructor/reference.html
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diff --git a/key-points.html b/key-points.html
index 2a5f1cefd..6de4eb8c6 100644
--- a/key-points.html
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   "dateCreated": "2016-01-07",
-  "dateModified": "2023-07-18",
-  "datePublished": "2023-07-18"
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index ee8a9b611..965989951 100644
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index 0f3785e5d..6050cf833 100644
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index eaf7738c7..18dd7af58 100644
--- a/profiles.html
+++ b/profiles.html
@@ -403,8 +403,8 @@ <h1>Learner Profiles</h1>
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   "dateCreated": "2016-01-07",
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diff --git a/reference.html b/reference.html
index 8562b192b..056ecb7ed 100644
--- a/reference.html
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@@ -821,7 +821,7 @@ <h3 class="code-label">PYTHON<i aria-hidden="true" data-feather="chevron-left"><
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