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你好，我是刚学习 python,版本是 python3.x 的,今天写了一个 const 的文件,用于定义常量,如果重复赋值就会报错,但是现在的问题是，报错信息却不是我的预期信息，请问是怎么回事呢?
const.py
====================================================
import sys
class ConstError(TypeError):pass
class _const(object):
def __setattr__(self,name,value):
if name in self.__dict__:
raise self.ConstError("Can't rebind const(%s)"%name)
self.__dict__[name]=value
sys.modules[__name__]=_const()
===================================================
useConst
===================================================
import const
const.value = 12
const.value = 13
print (const.value)
报错信息:
Traceback (most recent call last):
AttributeError:'_const'object has no attribute 'ConstError'
我的预期抛错信息应该是 Can't rebind const(value)的,请问是怎么回事呢?
const.py
====================================================
import sys
class ConstError(TypeError):pass
class _const(object):
def __setattr__(self,name,value):
if name in self.__dict__:
raise self.ConstError("Can't rebind const(%s)"%name)
self.__dict__[name]=value
sys.modules[__name__]=_const()
===================================================
useConst
===================================================
import const
const.value = 12
const.value = 13
print (const.value)
报错信息:
Traceback (most recent call last):
AttributeError:'_const'object has no attribute 'ConstError'
我的预期抛错信息应该是 Can't rebind const(value)的,请问是怎么回事呢?
 | 1 henryho914 OP 已解决................. class ConstError(TypeError):pass 这个类放错位置了 |
 | 2 xiangace Dec 3, 2015 安利下我的作品 kkconst |
| 3 xiangace Dec 3, 2015  1 |
| 4 henryho914 OP @xiangace 谢谢你的代码，学习了不少~ |
| 5 xiangace Dec 13, 2015 @henryho914 那个库实现的代码写复杂了, 可以看我的一篇文章, 由简单的需求衍生出来的库的历史, 大致上是一个演进的过程, 提供 metaclass 的使用案例, 可能帮助你理解你现在的场景需求. [ 应用于 Restful 接口的错误码设计 ErrorCode Class(Python) ]( http://www.kaka-ace.com/restful_api_error_code_design_for_python/) |
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