Merge pull request #17718 from meeseeksmachine/auto-backport-of-pr-17715-on-v3.3.x

tacaswell · web-flow · commit 46ac59ad7001 · 2020-06-22T13:26:54.000-04:00
Backport PR #17715 on branch v3.3.x (Clarify gridspec error message for non-integer inputs.)
diff --git a/lib/matplotlib/gridspec.py b/lib/matplotlib/gridspec.py
@@ -45,9 +45,11 @@ def __init__(self, nrows, ncols, height_ratios=None, width_ratios=None):
             If not given, all rows will have the same height.
         """
         if not isinstance(nrows, Integral) or nrows <= 0:
-            raise ValueError(f"Number of rows must be > 0, not {nrows}")
+            raise ValueError(
+                f"Number of rows must be a positive integer, not {nrows}")
         if not isinstance(ncols, Integral) or ncols <= 0:
-            raise ValueError(f"Number of columns must be > 0, not {ncols}")
+            raise ValueError(
+                f"Number of columns must be a positive integer, not {ncols}")
         self._nrows, self._ncols = nrows, ncols
         self.set_height_ratios(height_ratios)
         self.set_width_ratios(width_ratios)
diff --git a/lib/matplotlib/tests/test_figure.py b/lib/matplotlib/tests/test_figure.py
@@ -182,9 +182,11 @@ def test_gca():
 
 def test_add_subplot_invalid():
     fig = plt.figure()
-    with pytest.raises(ValueError, match='Number of columns must be > 0'):
+    with pytest.raises(ValueError,
+                       match='Number of columns must be a positive integer'):
         fig.add_subplot(2, 0, 1)
-    with pytest.raises(ValueError, match='Number of rows must be > 0'):
+    with pytest.raises(ValueError,
+                       match='Number of rows must be a positive integer'):
         fig.add_subplot(0, 2, 1)
     with pytest.raises(ValueError, match='num must be 1 <= num <= 4'):
         fig.add_subplot(2, 2, 0)
