method = Klass.othermethod considered PITA

[Steven Bethard]

Erik Max Francis wrote:
> For instance, for a chat network bot framework, a certain form of bot 
> will look for any attribute in its instance that starts with verb_ and a 
> command and execute it when it hears it spoken:
> 
>     def verb_hello(self, convo):
>         "Respond to a greeting."
>         convo.respond(random.choice(self.greetings))
> 
> If you'd like it to respond to more than one word like this, then you 
> only need to assign the additional verbs, rather than redefine them:
> 
>     verb_hi = verb_hello
>     verb_yo = verb_hello
>     verb_wazzup = verb_hello

Well if you want these to work with subclasses that change verb_hello to 
do something else, one option is to write a simple decorator, and then 
your lines above become something like:

     verb_hi = caller(verb_hello)
     verb_yo = caller(verb_hello)
     verb_wazzup = caller(verb_hello)

or if you prefer to only create one such function:

     _verb_hello_caller = caller(verb_hello)
     verb_hi = _verb_hello_caller
     verb_yo = _verb_hello_caller
     verb_wazzup = _verb_hello_caller

Here's a simple example in action:

py> def caller(func):
...     def wrapper(self, *args, **kwargs):
...         return getattr(self, func.__name__)(*args, **kwargs)
...     return wrapper
...
py> class C(object):
...     def verb_hello(self):
...         print "C: hello"
...     verb_hi = caller(verb_hello)
...
py> class D(C):
...     def verb_hello(self):
...         print "D: hello"
...
py> D().verb_hi()
D: hello

Notice that verb_hi() still calls verb_hello() in the subclass.

STeVe