remove six in cssSpecial
@@ -227,7 +227,7 @@ def parseSpecialRules(declarations, debug=0):
part = getNextPart(parts) or oparts
if part:
- if isinstance(part, six.string_types) and (("." in part) or ("data:" in part)):
+ if isinstance(part, str) and (("." in part) or ("data:" in part)):
dd.append(("background-image", part, last))
else:
dd.append(("background-color", part, last))
