Minor format tweaks

pymatviz/__init__.py

@@ -121,15 +121,14 @@
 # use pio.kaleido.scope.mathjax = None
 
 
-"""
-Importing this module has side-effects that apply sensible (often, not always) global
-defaults settings for plotly and matplotlib like increasing font size, prettier
-axis labels (plotly only) and higher figure resolution (matplotlib only).
+# Importing this module has side-effects that apply sensible (often, not always) global
+# defaults settings for plotly and matplotlib like increasing font size, prettier
+# axis labels (plotly only) and higher figure resolution (matplotlib only).
 
-To use it, simply import this module before generating any plots:
+# To use it, simply import this module before generating any plots:
+
+# import pymatviz
 
-import pymatviz
-"""
 
 plt.rc("font", size=16)
 plt.rc("savefig", bbox="tight", dpi=200)

pymatviz/histograms.py

@@ -286,7 +286,7 @@ def spacegroup_hist(
     for crys_sys, count, width, color in crys_sys_counts.itertuples():
         x1 = x0 + width
 
-        for patch in ax.patches[0 if x0 == 1 else x0 : x1 + 1]:
+        for patch in ax.patches[0 if x0 == 1 else x0: x1 + 1]:
             patch.set_facecolor(color)
 
         text_kwds = dict(transform=trans, horizontalalignment="center") | (

pymatviz/io.py

@@ -11,6 +11,7 @@
 import matplotlib.pyplot as plt
 import plotly.graph_objects as go
 from tqdm import tqdm
+from weasyprint import HTML
 
 
 if TYPE_CHECKING:
@@ -109,13 +110,13 @@ def save_fig(
         if path.lower().endswith(".svelte"):
             # insert {...$$props} into top-level div to be able to post-process and
             # style plotly figures from within Svelte files
-            with open(path) as file:
+            with open(path, encoding="utf-8") as file:
                 text = file.read().replace("<div>", "<div {...$$props}>", 1)
-            with open(path, "w") as file:
+            with open(path, "w", encoding="utf-8") as file:
                 # add trailing newline for pre-commit end-of-file commit hook
                 file.write(text + "\n")
         if style:
-            with open(path, "r+") as file:
+            with open(path, "r+", encoding="utf-8") as file:
                 # replace first '<div ' with '<div {style=} '
                 file.write(file.read().replace("<div ", f"<div {style=} ", 1))
     else:
@@ -203,12 +204,6 @@ def df_to_pdf(
             values CSS strings. Example: dict("td, th": "border: none; padding: 4px;")
         **kwargs: Keyword arguments passed to Styler.to_html().
     """
-    try:
-        from weasyprint import HTML
-    except ImportError as exc:
-        msg = "weasyprint not installed\nrun pip install weasyprint"
-        raise ImportError(msg) from exc
-
     if styler_css:
         styler_css = styler_css if isinstance(styler_css, dict) else DEFAULT_DF_STYLES
         styler.set_table_styles(
@@ -354,7 +349,7 @@ def df_to_html_table(
     if styles is not None:
         # insert styles at end of closing </style> tag so they override default styles
         html = html.replace("</style>", f"{styles}\n</style>")
-    with open(file_path, "w") as file:
+    with open(file_path, "w", encoding="utf-8") as file:
         file.write(html)
 
 

pymatviz/phonons.py

@@ -137,10 +137,10 @@ def plot_phonon_bands(
                 f"Only {PhononBands.__name__} objects supported, got {type_name}"
             )
         branches = {pretty_sym_point(branch["name"]) for branch in bs.branches}
-        if not common_branches:
-            common_branches = branches
-        else:
+        if common_branches:
             common_branches = common_branches & branches
+        else:
+            common_branches = branches
 
     if not common_branches:
         raise ValueError("No common branches found among the band structures.")

pymatviz/uncertainty.py

@@ -185,9 +185,7 @@ def get_std_decay(y_true: ArrayLike, y_pred: ArrayLike, y_std: ArrayLike) -> Arr
     # increasing count of the number of samples in each element of cumsum()
     n_inc = range(1, len(abs_err) + 1)
 
-    decay_by_std = abs_err[y_std_sort].cumsum() / n_inc
-
-    return decay_by_std  # noqa: RET504
+    return abs_err[y_std_sort].cumsum() / n_inc  # noqa: RET504
 
 
 def error_decay_with_uncert(

pymatviz/utils.py

@@ -299,23 +299,24 @@ def annotate_metrics(
 
 def crystal_sys_from_spg_num(spg: int) -> CrystalSystem:
     """Get the crystal system for an international space group number."""
-    # not using isinstance(n, int) to allow 0-decimal floats
-    if not (spg == int(spg) and 0 < spg < 231):
+    spg = int(spg)
+    if not 1 <= spg <= 230:
         raise ValueError(f"Invalid space group {spg}")
 
-    if 0 < spg < 3:
+    if 1 <= spg <= 2:
         return "triclinic"
-    if spg < 16:
+    elif spg <= 15:
         return "monoclinic"
-    if spg < 75:
+    elif spg <= 74:
         return "orthorhombic"
-    if spg < 143:
+    elif spg <= 142:
         return "tetragonal"
-    if spg < 168:
+    elif spg <= 167:
         return "trigonal"
-    if spg < 195:
+    elif spg <= 194:
         return "hexagonal"
-    return "cubic"
+    else:
+        return "cubic"
 
 
 def add_identity_line(