          ])
  
      def to_representation(self, value):
          return set([
              self.choice_strings_to_values[str(item)] for item in value
          ])
  
  
  # File types...
  
 
</s> remove             (str(key), key) for key in self.choices.keys()
 </s> add             (six.text_type(key), key) for key in self.choices.keys() </s> remove         orm_lookups = [self.construct_search(str(search_field))
 </s> add         orm_lookups = [self.construct_search(six.text_type(search_field)) </s> remove             value = decimal.Decimal(str(value).strip())
 </s> add             value = decimal.Decimal(six.text_type(value).strip()) </s> remove         return str(value).strip()
 </s> add         return six.text_type(value).strip()
            self.choice_strings_to_values[six.text_type(item)] for item in value
          ])
  
      def to_representation(self, value):
          return set([
            self.choice_strings_to_values[six.text_type(item)] for item in value
          ])
  
  
  # File types...
  
keep keep keep keep replace keep keep keep keep keep
 Use six.text_type instead of str everywhere 
rest_framework/fields.py