Attribute fallback in Python - useful when you cannot extend an existing class, or want a proxy

fallback.py

class Bar(object):
    def plop(self):
        print 'plop'

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

    def do(self):
        print 'done'

    def __getattribute__(self, attr):
        try:
            return object.__getattribute__(self, attr)
        except AttributeError as initial:
            try:
                return object.__getattribute__(self.bar, attr)
            except AttributeError:
                raise initial

>>> Foo().do()
done
>>> Foo().plop()
plop
>>> Foo().unexistent
AttributeError: 'Foo' object has no attribute 'unexistent'

maybe use hasattr(), instead of the try... except?

http://docs.python.org/library/functions.html#hasattr

... and/or gettattr?

You can't use them because they use __getattribute__ themselves… you'd be ending with recursion errors :)

ah. never mind, then