code: def _hincrby(self, hashkey, attribute, command, type_, increment):
          
          redis_hash = self._get_hash(hashkey, command, create=True)
          attribute = self._encode(attribute)
          previous_value = type_(redis_hash.get(attribute, '0'))
          redis_hash[attribute] = self._encode(previous_value + increment)
          return type_(redis_hash[attribute])
docs: Shared hincrby and hincrbyfloat routine