重写TupleEnum的__str__方法，让返回value

[maiyajj]

class SecretEnum(TupleEnum):
SECRET = "secret", "敏感"
NO_SECRET = "no_secret", "非敏感"

>>>print(str(SecretEnum.SECRET))
>>>SecretEnum.SECRET

重写__str__:
class TupleEnum:
def __str__(self):
return self.value

>>>print(str(SecretEnum.SECRET))
>>>"secret"