Is there an official way to add methods to an instance?

[Peter Otten]

Brian Vanderburg II wrote:

> I don't know if this is the correct place to send this question.

It is.
 
> I've checked out some ways to get this to work.  I want to be able to
> add a new function to an instance of an object.  I've tested two
> different methods that cause problems with 'deleting'/garbage collection
> (__del__ may never get called), but implemented one sort of hackishly
> maybe that works find. I'm wondering if there is more of an official way
> than mine.

[snip]

I think "Try hard to avoid __del__()" is as close to an official stance as
you can get ;)

Anyway, here is one more option to add too the zoo:

>>> class A(object):
...     def __init__(self, f, x):
...         self._f = f
...         self.x = x
...     @property
...     def f(self):
...         return self._f.__get__(self)
...     def __del__(self):
...         print "deleting"
...
>>> a = A(lambda s: s.x * 2, 2)
>>> b = A(lambda s: s.x * 3, 3)
>>> a.f()
4
>>> b.f()
9
>>> del a
deleting
>>> del b
deleting

Peter