def require_int (func):
def wrapper (arg):
assert isinstance(arg, int)
return func(arg)

return wrapper

@require_int
def p1 (arg):
print arg

@require_int
def p2(arg):
print arg*2


在python文档上讲python2.4上讲decorators有这么一段代码
我运行p1(1)为什么会报错
>>> p1(1)
Traceback (most recent call last):
File "", line 1, in ?
TypeError: 'NoneType' object is not callable

Python 2.4.3 (#69, Mar 29 2006, 17:35:34) [MSC v.1310 32 bit (Intel)] on
win32
Type "help", "copyright", "credits" or "license" for more information.
>>> def require_int(func):
...   def wrapper(arg):
...     assert isinstance(arg,int)
...     return func(arg)
...   return wrapper
...
>>> @require_int
... def p1(arg):
...   print arg
...
>>> p1(1)
1
>>>


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On 7/20/06, crocodile.liu <crocodile.liu at 163.com> wrote:
>
> def require_int (func):
> def wrapper (arg):
> assert isinstance(arg, int)
> return func(arg)
>
> return wrapper
>
> @require_int
> def p1 (arg):
> print arg
>
> @require_int
> def p2(arg):
> print arg*2
>
>
> 在python文档上讲python2.4上讲decorators有这么一段代码
> 我运行p1(1)为什么会报错
> >>> p1(1)
> Traceback (most recent call last):
> File "", line 1, in ?
> TypeError: 'NoneType' object is not callable
>

没有缩近啊。

-- 
I like python!
My Blog: http://www.donews.net/limodou
My Django Site: http://www.djangocn.org
NewEdit Maillist: http://groups.google.com/group/NewEdit

原来是直接粘上去的代码就不行了，手动在命令行中敲代码就好了


limodou 写道:
> On 7/20/06, crocodile.liu <crocodile.liu at 163.com> wrote:
>>
>> def require_int (func):
>> def wrapper (arg):
>> assert isinstance(arg, int)
>> return func(arg)
>>
>> return wrapper
>>
>> @require_int
>> def p1 (arg):
>> print arg
>>
>> @require_int
>> def p2(arg):
>> print arg*2
>>
>>
>> 在python文档上讲python2.4上讲decorators有这么一段代码
>> 我运行p1(1)为什么会报错
>> >>> p1(1)
>> Traceback (most recent call last):
>> File "", line 1, in ?
>> TypeError: 'NoneType' object is not callable
>>
>
> 没有缩近啊。
>
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