def make_clean_method(field_name):

    def _clean_method(self):
        value = self.cleaned_data[field_name]
        if value:
            self.cleaned_data[get_double_name(field_name)] = value
        return value
    return _clean_method
def make_clean_method(field_name):

    def _clean_method(self):
        value = self.cleaned_data[field_name]
        if value:
            self.cleaned_data[get_double_name(field_name)] = value
        return value
    return _clean_method