Fix string numbers in to_rgba() and is_color_like()

timhoffm · timhoffm · commit 368556285fe0 · 2019-04-10T01:21:53.000+02:00
diff --git a/lib/matplotlib/colors.py b/lib/matplotlib/colors.py
@@ -225,9 +225,14 @@ def _to_rgba_no_colorcycle(c, alpha=None):
             return tuple(color)
         # string gray.
         try:
-            return (float(c),) * 3 + (alpha if alpha is not None else 1.,)
+            c = float(c)
         except ValueError:
             pass
+        else:
+            if not (0 <= c <= 1):
+                raise ValueError(
+                    "String grayscale values must be within 0-1 range")
+            return (float(c),) * 3 + (alpha if alpha is not None else 1.,)
         raise ValueError("Invalid RGBA argument: {!r}".format(orig_c))
     # tuple color.
     c = np.array(c)
diff --git a/lib/matplotlib/tests/test_colors.py b/lib/matplotlib/tests/test_colors.py
@@ -471,12 +471,6 @@ def test_autoscale_masked():
     plt.draw()
 
 
-def test_colors_no_float():
-    # Gray must be a string to distinguish 3-4 grays from RGB or RGBA.
-    with pytest.raises(ValueError):
-        mcolors.to_rgba(0.4)
-
-
 @image_comparison(baseline_images=['light_source_shading_topo'],
                   extensions=['png'])
 def test_light_source_topo_surface():
@@ -756,6 +750,18 @@ def test_conversions():
         hex_color
 
 
+def test_failed_conversions():
+    with pytest.raises(ValueError):
+        mcolors.to_rgba('5')
+    with pytest.raises(ValueError):
+        mcolors.to_rgba('-1')
+    with pytest.raises(ValueError):
+        mcolors.to_rgba('nan')
+    with pytest.raises(ValueError):
+        # Gray must be a string to distinguish 3-4 grays from RGB or RGBA.
+        mcolors.to_rgba(0.4)
+
+
 def test_grey_gray():
     color_mapping = mcolors._colors_full_map
     for k in color_mapping.keys():
