set_map_layout: better errors for wrong type and subfigure (#121)

* set_map_layout: better errors for wrong type and subfigure

* CHANGELOG

Author: mathause

CHANGELOG.md

@@ -13,6 +13,8 @@
 ### Enhancements
 
 - Enable passing `AxesGrid` (from `mpl_toolkits.axes_grid1`) to `set_map_layout` ([#116](https://github.com/mathause/mplotutils/pull/116)).
+- Raise more informative error when a wrong type is passed to `set_map_layout` ([#121](https://github.com/mathause/mplotutils/pull/121)).
+- `set_map_layout` now raises an explicit error when the figure contains SubFigure ([#121](https://github.com/mathause/mplotutils/pull/121)).
 
 ## v0.5.0 (27.03.2024)
 

mplotutils/map_layout.py

@@ -1,5 +1,6 @@
 import warnings
 
+import matplotlib as mpl
 import matplotlib.pyplot as plt
 import numpy as np
 from mpl_toolkits.axes_grid1 import AxesGrid
@@ -50,20 +51,23 @@ def set_map_layout(obj=None, width=17.0, *, nrow=None, ncol=None, axes=None):
         _set_map_layout_axes(obj, width, nrow, ncol)
 
 
-def _set_map_layout_axes(axes, width, nrow, ncol):
+def _set_map_layout_axes(axs, width, nrow, ncol):
 
     if (nrow is None and ncol is not None) or (nrow is not None and ncol is None):
         raise ValueError("Must set none or both of 'nrow' and 'ncol'")
 
-    if isinstance(axes, plt.Axes):
-        ax = axes
-    else:
-        # assumes the first of the axes is representative for all
-        ax = np.asarray(axes).flat[0]
+    # assumes the first of the axes is representative for all
+    ax = np.asarray(axs).flat[0]
+
+    if not isinstance(ax, plt.Axes):
+        raise TypeError(f"Expected axes or an array of axes, got {type(ax)}")
 
     # read figure data
     f = ax.get_figure()
 
+    if isinstance(f, mpl.figure.SubFigure) or f.subfigs:
+        raise RuntimeError("matplotlib SubFigure not supported")
+
     # getting the correct data ratio of geoaxes requires draw
     f.canvas.draw()
 

mplotutils/tests/test_set_map_layout.py

@@ -25,6 +25,29 @@ def test_set_map_layout_deprecated_kwarg():
         set_map_layout(object, axes=object)
 
 
+def test_map_layout_not_axes_error():
+
+    with figure_context() as f:
+        with pytest.raises(TypeError, match="Expected axes or an array of axes"):
+            set_map_layout(f)
+
+    with pytest.raises(TypeError, match="Expected axes or an array of axes"):
+        set_map_layout(object)
+
+
+def test_map_layout_subfigures_error():
+
+    with figure_context() as f:
+        sf = f.subfigures(1, 1)
+        axs = sf.subplots(1, 2)
+
+        with pytest.raises(RuntimeError, match="matplotlib SubFigure not supported"):
+            set_map_layout(f.axes)
+
+        with pytest.raises(RuntimeError, match="matplotlib SubFigure not supported"):
+            set_map_layout(axs)
+
+
 def test_set_map_layout_default_width():
     with subplots_context() as (f, ax):
         set_map_layout(ax)