[Python-Dev] PEP 326 (quick location possibility) (original) (raw)

Tim Peters tim.one at comcast.net
Thu Jan 29 11:04:00 EST 2004

[Tim'

... There are few enough bugs in my code at this age that I take very seriously any principled gimmick that could prevent repeating one.

[Raymond]

Alex Martelli had proposed extending the key= idea to min() and max(). The idea is to let those functions completely encapsulate the logic of searching for minimum and maximum elements:

bestplayer = min(players, key=attrgetter('points')) This would work equally well with other objective functions.

Different issue. I didn't have "a sequence". The loop was more like:

global_minimum = made_up_value_presumed_to_be_unreachably_large
while mote_to_look_at:
    do a ton of computation, yielding a candidate
    if score(candidate) < global_minimum:
        global_minimum = score(candidate)
        do a ton of stuff to prune the search based
            on the new (so far) local minimum
return global_minimum

It's picking the made_up_value_presumed_to_be_unreachably_large that's a brittle hack, and is specifically the source of the bug I mentioned. Adding new twists to min() wouldn't have made any difference to that.

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