Simplify validate_color_for_prop_cycle.

anntzer · anntzer · commit c5c0f493e4ad · 2020-03-10T08:01:23.000+01:00
No need to special case bytes -- validate_colors is going to raise a
TypeError on bytes input anyways (_is_nth_color checks that the input is
str as well).
diff --git a/doc/api/next_api_changes/behaviour.rst b/doc/api/next_api_changes/behaviour.rst
@@ -100,4 +100,9 @@ deprecation warning.
 
 Previously setting the *ecolor* would turn off automatic color cycling for the plot, leading to the 
 the lines and markers defaulting to whatever the first color in the color cycle was in the case of 
-multiple plot calls. 
+multiple plot calls. 
+
+`.rcsetup.validate_color_for_prop_cycle` now always raises TypeError for bytes input
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+It previously raised `TypeError`, **except** when the input was of the form
+``b"C[number]"`` in which case it raised a ValueError.
diff --git a/lib/matplotlib/rcsetup.py b/lib/matplotlib/rcsetup.py
@@ -322,18 +322,9 @@ def validate_color_or_auto(s):
 
 
 def validate_color_for_prop_cycle(s):
-    # Special-case the N-th color cycle syntax, this obviously can not
-    # go in the color cycle.
-    if isinstance(s, bytes):
-        match = re.match(b'^C[0-9]$', s)
-        if match is not None:
-            raise ValueError('Can not put cycle reference ({cn!r}) in '
-                             'prop_cycler'.format(cn=s))
-    elif isinstance(s, str):
-        match = re.match('^C[0-9]$', s)
-        if match is not None:
-            raise ValueError('Can not put cycle reference ({cn!r}) in '
-                             'prop_cycler'.format(cn=s))
+    # N-th color cycle syntax can't go into the color cycle.
+    if isinstance(s, str) and re.match("^C[0-9]$", s):
+        raise ValueError(f"Cannot put cycle reference ({s!r}) in prop_cycler")
     return validate_color(s)
 
 
