Why is lambda allowed as a key in a dict?

[Paul Rubin]

Craig Allen <callen314 at gmail.com> writes:
> it raises an interesting question about why doesn't it.  I can think
> of practical answers to that, obviously, but in principle, if a
> function compiles to exactly the same byte code, you obviously do not
> need two copies of it, and like strings shouldn't an identical
> function have the same id?

Identical strings don't necessarily have the same id:

    >>> a = "a"*1000
    >>> b = "a"*1000
    >>> id(a),id(b)
    (137143648, 137144680)
    >>> a==b
    True