String Validator

String Validator from the pagure/validators.py:

class StringValidator(object):
    """Validates input to be a string"""

    def __init__(self, message="This field needs to be a string"):
        self._message = message

    def __call__(self, form, stringfield):
        if type(stringfield.data) != six.text_type:
            raise validators.ValidationError(
                "{0} Found {1}".format(self._message, stringfield.data)
            )