MNT: remove None from value checks

tacaswell · tacaswell · commit 2935b99c92ba · 2016-12-04T16:40:05.000-05:00
`None` used to be a valid value for the style/slant and variant, however in cc61700 the behavior was changed to look up the defaults as set time (not get time) so there is no reason to allow invalid values to be set to the internal state.
diff --git a/lib/matplotlib/font_manager.py b/lib/matplotlib/font_manager.py
@@ -835,7 +835,7 @@ def set_style(self, style):
         """
         if style is None:
             style = rcParams['font.style']
-        if style not in ('normal', 'italic', 'oblique', None):
+        if style not in ('normal', 'italic', 'oblique'):
             raise ValueError("style must be normal, italic or oblique")
         self._slant = style
     set_slant = set_style
@@ -846,7 +846,7 @@ def set_variant(self, variant):
         """
         if variant is None:
             variant = rcParams['font.variant']
-        if variant not in ('normal', 'small-caps', None):
+        if variant not in ('normal', 'small-caps'):
             raise ValueError("variant must be normal or small-caps")
         self._variant = variant
 
