function-indirection.py

#!/usr/bin/env python3

# using inspect
from inspect import currentframe, getframeinfo
class Foo:
    def __init__(self, quux):
        self.quux = quux

    def bar(self):
        return getframeinfo(currentframe()).function, self.quux

assert Foo('spam').bar() == ('bar', 'spam')

# using __getattr__
class Foo:
    def __init__(self, quux):
        self.quux = quux

    def __getattr__(self, attr):
        if attr == 'bar':
            def bar():
                # self bound via closure
                return attr, self.quux
            return bar
        return super().__getattribute__(self, attr)

assert Foo('spam').bar() == ('bar', 'spam')

# using a descriptor
class Foo:
    def __init__(self, quux):
        self.quux = quux

    class bar:
        def __get__(descr, self, instance):
            def bar():
                # self bound via closure
                return type(descr).__name__, self.quux
            return bar
    bar = bar()

assert Foo('spam').bar() == ('bar', 'spam')

# using a decorator
from functools import wraps

def dec(func):
    @wraps(func)
    def wrapped(*args, **kwargs):
        rv = func(*args, **kwargs)
        return func.__name__, rv
    return wrapped

class Foo:
    def __init__(self, quux):
        self.quux = quux

    @dec
    def bar(self):
        return self.quux

assert Foo('spam').bar() == ('bar', 'spam')