ranges.py 文件源码

def compress(self, values):
        if not values:
            return None
        lower, upper = values
        if lower is not None and upper is not None and lower > upper:
            raise exceptions.ValidationError(
                self.error_messages['bound_ordering'],
                code='bound_ordering',
            )
        try:
            range_value = self.range_type(lower, upper)
        except TypeError:
            raise exceptions.ValidationError(
                self.error_messages['invalid'],
                code='invalid',
            )
        else:
            return range_value