why __repr__ affected after __getattr__ overloaded?
Gabriel Genellina
gagsl-py2 at yahoo.com.ar
Fri Jun 22 02:58:32 EDT 2007
En Fri, 22 Jun 2007 02:48:50 -0300, Roc Zhou <chowroc.z at gmail.com>
escribió:
> I know what's wrong. Thank you. And I think
> try:
> return self.__dict__[attr_name]
> is unnecessary, because python will do it itself for us.
Exactly; by the time __getattr__ is called, you already know attr_name is
not there.
> So now I have to overload __str__, but how can I make self.__str__
> print as builtin str(): at here, I want get the result like:
> <test instance at 0xb7bbb90c>
> ?
I would do the opposite: *only* create inexistent attributes when they are
not "special". This way you don't mess with Python internals.
... def __getattr__(self, name):
... if name[:2]!='__' or name[-2:]!='__':
... self.__dict__[name] = 'inexistent'
... return self.__dict__[name]
... raise AttributeError,name
This way you don't create "fake" attributes for things like __bases__ by
example, and dir(), vars(), repr() etc. work as expected.
--
Gabriel Genellina
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