Bypassing __getattribute__ for attribute access

[Chris Mellon]

On Thu, 2007-10-25 at 23:13 +0200, Bruno Desthuilliers wrote:
<snip excellent breakdown>

> > The logical next question then is how does one best add a new method
> > to this class so that future references to x.set_x() and X.set_x will
> > properly resolve?  It seems the answer would be to somehow add to
> > X.__dict__ a new value, with key 'set_x', value the function set_x.
> 
> Yes. Which is very simply done by just binding set_x to X.set_x. Just 
> like I did above. Dynamically adding methods to classes is pretty 
> straightforward, the tricky point is to dynamically add methods to 
> instances, since the descriptor protocol is only triggered for class 
> attributes. But you obviously found how to do it using func.__get__(obj, 
> type(obj)) !-)
> 

This is the greasy, getting your hands dirty way. I vastly prefer (and
reccomend) using the new module:

>>> import new
>>> class X(object):
...     pass
...     
>>> def bar(self):
...     print self
...     
>>> x = X()
>>> x.bar = new.instancemethod(bar, x, X)
>>> x.bar()
<__main__.X object at 0x87dca0c>
>>> 



> >>From there on the . operator I assume would perform the binding to X
> > or x as needed on-the-fly.
> 
> Yes.
> 
> NB: please some guru around correct me if I said something wrong (Alex ? 
> Tim ? Fredrick ? If you hear me ?)