breaking: Change coord_iter to return tuple[content, pos]

Co-authored-by: rht <rhtbot@protonmail.com>

docs/tutorials/intro_tutorial.ipynb

@@ -788,7 +788,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "Now let's use matplotlib and numpy to visualize the number of agents residing in each cell. To do that, we create a numpy array of the same size as the grid, filled with zeros. Then we use the grid object's `coord_iter()` feature, which lets us loop over every cell in the grid, giving us each cell's coordinates and contents in turn."
+    "Now let's use matplotlib and numpy to visualize the number of agents residing in each cell. To do that, we create a numpy array of the same size as the grid, filled with zeros. Then we use the grid object's `coord_iter()` feature, which lets us loop over every cell in the grid, giving us each cell's positions and contents in turn."
    ]
   },
   {
@@ -805,8 +805,7 @@
     "import numpy as np\n",
     "\n",
     "agent_counts = np.zeros((model.grid.width, model.grid.height))\n",
-    "for cell in model.grid.coord_iter():\n",
-    "    cell_content, x, y = cell\n",
+    "for cell_content, (x, y) in model.grid.coord_iter():\n",
     "    agent_count = len(cell_content)\n",
     "    agent_counts[x][y] = agent_count\n",
     "# Plot using seaborn, with a size of 5x5\n",

mesa/space.py

@@ -193,11 +193,11 @@ def __iter__(self) -> Iterator[GridContent]:
         as if it is one list:"""
         return itertools.chain(*self._grid)
 
-    def coord_iter(self) -> Iterator[tuple[GridContent, int, int]]:
-        """An iterator that returns coordinates as well as cell contents."""
+    def coord_iter(self) -> Iterator[tuple[GridContent, Coordinate]]:
+        """An iterator that returns positions as well as cell contents."""
         for row in range(self.width):
             for col in range(self.height):
-                yield self._grid[row][col], row, col  # agent, x, y
+                yield self._grid[row][col], (row, col)  # agent, position
 
     def iter_neighborhood(
         self,

tests/test_grid.py

@@ -134,15 +134,13 @@ def test_coord_iter(self):
         # no agent in first space
         first = next(ci)
         assert first[0] is None
-        assert first[1] == 0
-        assert first[2] == 0
+        assert first[1] == (0, 0)
 
         # first agent in the second space
         second = next(ci)
         assert second[0].unique_id == 1
         assert second[0].pos == (0, 1)
-        assert second[1] == 0
-        assert second[2] == 1
+        assert second[1] == (0, 1)
 
     def test_agent_move(self):
         # get the agent at [0, 1]
@@ -480,8 +478,9 @@ def test_neighbors(self):
 class TestIndexing:
     # Create a grid where the content of each coordinate is a tuple of its coordinates
     grid = SingleGrid(3, 5, True)
-    for _, x, y in grid.coord_iter():
-        grid._grid[x][y] = (x, y)
+    for _, pos in grid.coord_iter():
+        x, y = pos
+        grid._grid[x][y] = pos
 
     def test_int(self):
         assert self.grid[0][0] == (0, 0)

tests/test_visualization.py

@@ -40,7 +40,8 @@ def __init__(self, width, height, key1=103, key2=104):
         self.schedule = SimultaneousActivation(self)
         self.grid = MultiGrid(width, height, torus=True)
 
-        for _c, x, y in self.grid.coord_iter():
+        for _c, pos in self.grid.coord_iter():
+            x, y = pos
             a = MockAgent(x + y * 100, self, x * y * 3)
             self.grid.place_agent(a, (x, y))
             self.schedule.add(a)