Lisp mentality vs. Python mentality

[bearophileHUGS at lycos.com]

You can also use quite less code, but this is less efficient:

def equal_items(iter1, iter2, key=lambda x: x):
    class Guard(object): pass
    try:
        for x, y in izip_longest(iter1, iter2, fillvalue=Guard()):
            if key(x) != key(y):
                return False
    except TypeError: # intercepts key(guard)
        return False
    return True

Bye,
bearophile