at the suggestion of @tacaswell, I'm just adding this auto-generated macosx.py file to the ignore list with it's compadres.

Author: katyhuff

Diff for: lib/matplotlib/tests/test_coding_standards.py

@@ -35,7 +35,8 @@
                  '_gtkagg.py',
                  '_backend_gdk.py',
                  'pyparsing*',
-                 '_qhull.py']
+                 '_qhull.py',
+                 '_macosx.py']
 
 PEP8_ADDITIONAL_IGNORE = ['E111',
                           'E112',