MAINT: mappingview check for Python 3.4

matthew-brett · matthew-brett · commit dfce0b23e7a4 · 2017-02-28T20:10:53.000-08:00
Python 3.4 does not automatically import module `abc` into
`collections`, causing an error when checking for
`collections.abc.MappingView`.  Use `collections.MappingView` to work
round this difference.

At some point Python may deprecate `collections.MappingView` in favor of
`collections.abc.MappingView` but we can fix that when it arises.
diff --git a/lib/matplotlib/cbook/__init__.py b/lib/matplotlib/cbook/__init__.py
@@ -2281,9 +2281,7 @@ def safe_first_element(obj):
 
 def sanitize_sequence(data):
     """Converts dictview object to list"""
-    if six.PY3 and isinstance(data, collections.abc.MappingView):
-        return list(data)
-    return data
+    return list(data) if isinstance(data, collections.MappingView) else data
 
 
 def normalize_kwargs(kw, alias_mapping=None, required=(), forbidden=(),
