Message137663
2011/6/4 Benjamin Peterson <report@bugs.python.org>:
> 2011/6/4 Soren Hansen <report@bugs.python.org>:
>> So my question is: If this change stays (which seems clear given that the only changes proposed here are ways of relaxing the type requirement of the __dir__ method's return value, not reverting the change altogether), and I have an old-style class with a __getattr__ defined, how do I make that class return whatever it would have usually returned for __dir__()?
>
> Yes, this is a limitation of magic methods on old style classes. The
> usual method is something like this:
>
> def __getattr__(self, name):
> if name == "__dir__":
> return self.__dir__
> # Other stuff
>
> Of course, the best fix is to use new-style classes. :)
If I do this:
===== test.py ======
class Foo:
def __getattr__(self, name):
if name == '__dir__':
return self.__dir__
return 'something else'
a = Foo()
print dir(a)
====================
After a lot of this:
File "test.py", line 4, in __getattr__
return self.__dir__
File "test.py", line 4, in __getattr__
return self.__dir__
File "test.py", line 4, in __getattr__
return self.__dir__
...I end up with a "RuntimeError: maximum recursion depth exceeded". I
can't say I'm surprised :) |
|
Date |
User |
Action |
Args |
2011-06-04 22:13:08 | soren | set | recipients:
+ soren, barry, rhettinger, jcea, ncoghlan, benjamin.peterson, eric.araujo, Arfrever, r.david.murray, michael.foord, Trundle |
2011-06-04 22:13:07 | soren | link | issue12248 messages |
2011-06-04 22:13:07 | soren | create | |
|