Raymond Hettinger <rhettin...@users.sourceforge.net> added the comment:
Thanks for the thoughtful reply. To give the idea another chance, today, I showed a code example to another experienced programmer. "What does this function return? max([-2, 5], start=0) " The person had a hard time making any sense of it. Perhaps the start argument was an index, or starting position, or a ceiling, or a floor. I'm rejecting the feature request for several reasons: * the code sample doesn't have obvious meaning to experienced programmers * the API of the min/max functions is already too complex -- the language needs to be easy to learn and remember * the start keyword argument doesn't interact well with the other features (such as the key argument or positional arguments). Mark questioned whether the key function would apply to the start value (any answer is arbitrary because either could work). Also, there was a question of how it would work with *args (does it change the case with zero arguments as it does for the iterator case). When the choice of semantics are arbitrary, it is better not to guess and instead have the coder explicitly say what is supposed to happen. * it isn't really needed, there are several existing ways to create the same effect. * the meaning of "start" is ambiguous and arbitrary (is it a default value for an empty input or it is like adding an extra value to the input sequence). We could pick one of the two meanings but that doesn't help a coder or code reviewer remember which meaning was correct. To prevent bugs, it is better for the code to explicitly spell-out how the corner case is to be handled. * in mathematical notation, I see the corner cases being handled by piecewise functions (if seq is empty, value is this, else compute min/max) instead of the notation trying to override the simple meaning of min/max. * I haven't found precendents in any other language. Even if there were, we would still have the problem of too many features being loaded onto Python's min/max and the unclear semantics of how those features would interact. Thank you for the feature request. Sorry, this one didn't pan out. ---------- resolution: -> rejected status: open -> closed _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue7153> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
