Change what the *splat and **splatty-splat operators do to my object

Question

How do you override the result of unpacking syntax *obj and **obj?

For example, can you somehow create an object thing which b

Answer 1

I did succeed in making an object that behaves how I described in my question, but I really had to cheat. So just posting this here for fun, really -

class Thing:
    def __init__(self):
        self.mode = 'abc'
    def __iter__(self):
        if self.mode == 'abc':
            yield 'a'
            yield 'b'
            yield 'c'
            self.mode = 'def'
        else:
            yield 'd'
            yield 'e'
            yield 'f'
            self.mode = 'abc'
    def __getitem__(self, item):
        return 'I am a potato!!'
    def keys(self):
        return ['hello world']

The iterator protocol is satisfied by a generator object returned from __iter__ (note that a Thing() instance itself is not an iterator, though it is iterable). The mapping protocol is satisfied by the presence of keys() and __getitem__. Yet, in case it wasn't already obvious, you can't call *thing twice in a row and have it unpack a,b,c twice in a row - so it's not really overriding splat like it pretends to be doing.