En Fri, 13 Feb 2009 08:43:03 -0200, Peter Otten <__pete...@web.de> escribió:
Gabriel Genellina wrote:
En Fri, 13 Feb 2009 08:07:58 -0200, Carl Banks <pavlovevide...@gmail.com>
escribió:
But that brings up another very slight possibility, though not a very
likely one in this case: the behavior of isinstance can be
customized.  It can happen unbeknownst to a user who subclasses a
class that does that.

Really? I didn't know that -- how do you do that?

class Type(type):
...     def __instancecheck__(self, other): return True
...
class A(metaclass=Type): pass
...
class B: pass
...
isinstance(B(), A)
True

See also

http://www.python.org/dev/peps/pep-3119/#overloading-isinstance-and-issubclass

Ah, ok. Isn't menctioned in the main documentation though.

--
Gabriel Genellina

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