Injecting methods from one object to another

[Alex Martelli]

"Dan Schmidt" <dfan at harmonixmusic.com> wrote in message
news:wku2c00xlb.fsf at turangalila.harmonixmusic.com...
> I want to copy method x from object foo to object bar.
    [snip]
>   foo.x = bar.x
> doesn't work, because foo.x is still bound to bar:

Right, bar.x is a bound-method.

> The only problem is that foo.x is returning a function, not a method
> bound to foo.  I thought that if x was a function member of foo, then
> foo.x would automatically bind it, but it's not.

The magical-morphing behaviour in question happens when you
assign a function to a _class_, but not when you assing it to an
_instance_.

> I'm sure that I'm almost there and that there's a very simple
> solution, but I can't find it.  Anyone have the answer?

I think that's part of what the dreaded 'new' module lets you do:

class Bar:
    def __init__(self):
        self.who='Bar!'
    def meth(self):
        print "meth here",self.who

class Foo:
    def __init__(self):
        self.who='Foo!'

bar=Bar()
foo=Foo()

bar.meth()

import new
foo.meth=new.instancemethod(bar.meth.im_func,foo,Foo)
foo.meth()


Alex