code: def regex_validation_sealer(fields, defaults, RegexType=type(re.compile(""))):
      
      required = set(fields) - set(defaults)
      if required:
          raise TypeError(
              "regex_validation_sealer doesn't support required arguments. Fields that need fixing: %s" % required)
  
      klass = None
      kwarg_validators = dict(
          (key, val if isinstance(val, RegexType) else re.compile(val)) for key, val in defaults.items()
      )
      arg_validators = list(
          kwarg_validators[key] for key in fields
      )
  
      def __init__(self, *args, **kwargs):
          for pos, (value, validator) in enumerate(zip(args, arg_validators)):
              if not validator.match(value):
                  raise ValidationError("Positional argument %s failed validation. %r doesn't match regex %r" % (
                      pos, value, validator.pattern
                  ))
          for key, value in kwargs.items():
              if key in kwarg_validators:
                  validator = kwarg_validators[key]
                  if not validator.match(value):
                      raise ValidationError("Keyword argument %r failed validation. %r doesn't match regex %r" % (
                          key, value, validator.pattern
                      ))
          super(klass, self).__init__(*args, **kwargs)
  
      klass = type("RegexValidateBase", (__base__,), dict(
          __init__=__init__,
      ))
      return klass
docs: Example sealer that just does regex-based validation.