'Clear card data on validation errors
This requires the form was created by passing in a mutable QueryDict
instance, see :py:class:`readthedocs.payments.mixin.StripeMixin`'

def clear_card_data(self):

    try:
        self.data['stripe_token'] = None
    except AttributeError:
        raise AttributeError('Form    was    passed    immutable    QueryDict    POST    data')
