          self[len(self):] = vals
  
      def insert(self, index, val):
          "Standard list insert method"
          if not isinstance(index, six.integer_types):
              raise TypeError("%s is not a legal index" % index)
          self[index:index] = [val]
  
      def pop(self, index=-1):
          "Standard list pop method"
 
</s> remove         if isinstance(index, six.integer_types):
 </s> add         if isinstance(index, int): </s> remove         if not isinstance(index, six.integer_types + (slice,)):
 </s> add         if not isinstance(index, (int, slice)): </s> remove         if not isinstance(index, (slice,) + six.integer_types):
 </s> add         if not isinstance(index, (int, slice)): </s> remove         if isinstance(index, six.string_types):
 </s> add         if isinstance(index, str): </s> remove             if isinstance(bcc, six.string_types):
 </s> add             if isinstance(bcc, str):
        if not isinstance(index, int):
          self[len(self):] = vals
  
      def insert(self, index, val):
          "Standard list insert method"
        if not isinstance(index, int):
              raise TypeError("%s is not a legal index" % index)
          self[index:index] = [val]
  
      def pop(self, index=-1):
          "Standard list pop method"
keep keep keep keep replace keep keep keep keep keep
 Refs #23919 -- Removed six.<various>_types usage

Thanks Tim Graham and Simon Charette for the reviews. 
django/contrib/gis/geos/mutable_list.py