Disclaimer This is just an exercise in meta-programming, it has no practical purpose.

I've assigned __getitem__ and __getattr__ methods on a function object, but there is no effect...

def foo():print "foo!"foo.__getitem__ = lambda name: name
foo.__getattr__ = lambda name: name
foo.baz = 'baz'

Sanity check that we can assign properties to a function:

>>> foo.baz
'baz'

Neat. How about the "magic getters"?

>>> foo.bar
Traceback (most recent call last):File "<stdin>", line 1, in <module>
AttributeError: 'function' object has no attribute 'bar'>>> foo['foo']
Traceback (most recent call last):File "<stdin>", line 1, in <module>
TypeError: 'function' object is not subscriptable>>> getattr(foo, 'bar')
Traceback (most recent call last):File "<stdin>", line 1, in <module>
AttributeError: 'function' object has no attribute 'bar'

Is it possible to have a "magic getter" on a function object?

Nope! Assigning __getitem__ to an instance doesn't work on any type of object:

>>> class A(object):
...   pass
...
>>> a = A()
>>> a.__getattr__ = lambda name: name
>>> a.foo
Traceback (most recent call last):File "<stdin>", line 1, in <module>
AttributeError: 'A' object has no attribute 'foo'

And you can't define __getattr__ on the built-in function type:

>>> import types
>>> types.FunctionType.__getitem__ = lambda name: name
Traceback (most recent call last):File "<stdin>", line 1, in <module>
TypeError: can't set attributes of built-in/extension type 'function'

And you can't subclass types.FunctionType:

>>> import types
>>> class F(types.FunctionType):
...   pass
... 
Traceback (most recent call last):File "<stdin>", line 1, in <module>
TypeError: Error when calling the metaclass bases
type 'function' is not an acceptable base type