fields.py 文件源码

def validate(self, value):
        if not isinstance(value, (six.binary_type, six.text_type, Binary)):
            self.error('BinaryField only accepts instances of '
                       '(%s, %s, Binary)' % (
                           six.binary_type.__name__, six.text_type.__name__))

        if self.max_bytes is not None and len(value) > self.max_bytes:
            self.error('Binary value is too long')