Manipulating caller frame

[Lulu of the Lotus-Eaters]

bokr at oz.net (Bengt Richter) wrote previously:
|ISTM the key issue is being able to write an abbreviation for something
|to be done more than once **within the current scope**. An ordinary
|function can't do that for several reasons.

Along those lines, the following rather shocks me:

    % cat change_foo.py
    def change_foo():
        import inspect
        caller_locals = inspect.currentframe(1).f_locals
        caller_locals['foo'] = 'newfoo'
        return caller_locals

    def somefunc():
        baz = 'bat'
        foo = 'bar'
        print foo
        l = change_foo()
        print foo
        print l, locals()
        print id(l), id(locals())

    somefunc()

    % python change_foo.py
    bar
    bar
    {'foo': 'newfoo', 'baz': 'bat'} {'l': {...}, 'baz': 'bat', 'foo': 'bar'}
    584780 584780

I can accept easily enough (if this is so) that 'caller_locals' is
really only a copy of the locals() dictionary.  Which would explain why
changing it doesn't change 'foo'.

But what I just can't get my head around is the idea that the 'l' and
'locals()' have the SAME ID, and yet different contents.

Can someone help me here?

Yours, Lulu...