看到SQLStorage.py有如下函数：
getattr(aq_parent, 'UID', lambda: None)()
请问如何解释？

好象是从aq_parent从查找UID方法，如果没找到返回lambda(不过有些怪没有试)，然后执行，因为后面有()

在 05-7-7，Person<person.lee at gmail.com> 写道：
> 看到SQLStorage.py有如下函数：
> getattr(aq_parent, 'UID', lambda: None)()
> 请问如何解释？
> 
> _______________________________________________
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> python-chinese at lists.python.cn
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> 
> 
> 


-- 
I like python! 
My Donews Blog: http://www.donews.net/limodou
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其实就相当于

try:
  aq_parent.UID()
except AttributeError:
  pass

lambda: None 就是一个返回None的函数


On 7/7/05, limodou <limodou at gmail.com> wrote:
> 好象是从aq_parent从查找UID方法，如果没找到返回lambda(不过有些怪没有试)，然后执行，因为后面有()
> 
> 在 05-7-7，Person<person.lee at gmail.com> 写道：
> > 看到SQLStorage.py有如下函数：
> > getattr(aq_parent, 'UID', lambda: None)()
> > 请问如何解释？
> >
> > _______________________________________________
> > python-chinese list
> > python-chinese at lists.python.cn
> > http://python.cn/mailman/listinfo/python-chinese
> >
> >
> >
> 
> 
> --
> I like python!
> My Donews Blog: http://www.donews.net/limodou
> New Google Maillist: http://groups-beta.google.com/group/python-cn
> 
> _______________________________________________
> python-chinese list
> python-chinese at lists.python.cn
> http://python.cn/mailman/listinfo/python-chinese
> 
> 
> 


-- 
Qiangning Hong

I'm usually annoyed by IDEs because, for instance, they don't use VIM
as an editor. Since I'm hooked to that, all IDEs I've used so far have
failed to impress me.
   -- Sybren Stuvel @ c.l.python

Get Firefox! <http://www.spreadfirefox.com/?q=affiliates&id=67907&t=1>

lambda:None就是一个返回None的函数，确实如此：
>>> f = lambda:None
>>> print f()
None

谢谢！
在 05-7-7，Qiangning Hong<hongqn at gmail.com> 写道：
> 其实就相当于
> 
> try:
>  aq_parent.UID()
> except AttributeError:
>  pass
> 
> lambda: None 就是一个返回None的函数
> 
> 
> On 7/7/05, limodou <limodou at gmail.com> wrote:
> > 好象是从aq_parent从查找UID方法，如果没找到返回lambda(不过有些怪没有试)，然后执行，因为后面有()
> >
> > 在 05-7-7，Person<person.lee at gmail.com> 写道：
> > > 看到SQLStorage.py有如下函数：
> > > getattr(aq_parent, 'UID', lambda: None)()
> > > 请问如何解释？
> > >
> > > _______________________________________________
> > > python-chinese list
> > > python-chinese at lists.python.cn
> > > http://python.cn/mailman/listinfo/python-chinese
> > >
> > >
> > >
> >
> >
> > --
> > I like python!
> > My Donews Blog: http://www.donews.net/limodou
> > New Google Maillist: http://groups-beta.google.com/group/python-cn
> >
> > _______________________________________________
> > python-chinese list
> > python-chinese at lists.python.cn
> > http://python.cn/mailman/listinfo/python-chinese
> >
> >
> >
> 
> 
> --
> Qiangning Hong
> 
> I'm usually annoyed by IDEs because, for instance, they don't use VIM
> as an editor. Since I'm hooked to that, all IDEs I've used so far have
> failed to impress me.
>   -- Sybren Stuvel @ c.l.python
> 
> Get Firefox! <http://www.spreadfirefox.com/?q=affiliates&id=67907&t=1>
> 
> _______________________________________________
> python-chinese list
> python-chinese at lists.python.cn
> http://python.cn/mailman/listinfo/python-chinese
> 
> 
>