Guido van Rossum added the comment:
id(a.__abs__) == id(a.__abs__)
has a completely different explanation -- it so happens that the first
instantiation of a.__abs__ is freed after id() is called on it and the
second instantiation happens to reuse that same memory block.
--
nosy:
Amaury Forgeot d'Arc added the comment:
It's actually documented in
http://docs.python.org/dev/reference/datamodel.html
Note that the transformation from function object to (unbound or bound)
method object happens each time the attribute is retrieved from the
class or instance
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Georg Brandl added the comment:
Yes, it is expected since the descriptor access to methods creates a new
bound method object every time. The is operator does not work special
with methods.
There is another issue about documenting this, so closing as a duplicate.
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nosy: +georg.brandl
New submission from Alexander Shigin:
Hello,
The operator is works strange with methods, i.e.:
a = 1
a.__abs__ is a.__abs__
False
If this is the preferred behavior by some reasons, I think
documentation should explain it.
It was tested on python 2.4.4, 2.5.1 and trunk r60477.
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Alexander Shigin added the comment:
I think it's good idea to make a note in Comparisons section or make
some reference to data model section.
The operators is and is not test for object identity: x is y is true if
and only if x and y are the same object. x is not y yields the inverse
truth
