python decorator example

gistfile1.py

#!/usr/bin/env python
#
# vim:syntax=python:sw=4:ts=4:expandtab

import functools

def wrap(orig_func):
    # now some funky python magic
    @functools.wraps(orig_func)
    def outer(new_func):
        def wrapper(*args, **kwargs):
            return new_func(orig_func, *args, **kwargs)
        setattr(orig_func.im_class, orig_func.__name__, wrapper)
        return wrapper
    return outer


class Foo(object):
    def __init__(self, bar):
        self.bar = bar

    def foo(self, arg):
        print 'Foo.foo()', self.bar, arg

Foo(23).foo(42)
print

@wrap(Foo.foo)
def new_foo(forig, self, arg):
    print '-> enter new_foo', arg
    forig(self, arg * 100)
    print '<- leave new_foo'


Foo(23).foo(42)