code: def make_pattern(self, pattern, listsep=','):
          
          if self is Cardinality.one:
              return pattern
          elif self is Cardinality.zero_or_one:
              return self.schema % pattern
          else:
              return self.schema % (pattern, listsep, pattern)
docs: Make pattern for a data type with the specified cardinality.
  
          .. code-block:: python
  
              yes_no_pattern = r"yes|no"
              many_yes_no = Cardinality.one_or_more.make_pattern(yes_no_pattern)
  
          :param pattern:  Regular expression for type (as string).
          :param listsep:  List separator for multiple items (as string, optional)
          :return: Regular expression pattern for type with cardinality.