Steven D'Aprano <steve+pyt...@pearwood.info> added the comment:
In your first example, `min([(-5, 2), (0, 2)])` the min() function compares the two tuples and finds that the first one is lexicographically smaller: py> (-5, 2) < (0, 2) True so (-5, 2) is considered the minimum. In the second example, using the key function compares 2 with 2, but since they are equal, the *first* tuple wins and is considered the minimum, and so using the key function doesn't change the result. In your third example, after reversing the list, you have `min([(0, 2), (-5, 2)])` and the min() function compares the two tuples and finds the *second* tuple is the smaller: py> (0, 2) < (-5, 2) False But in the fourth example, using the key function, yet again the comparison compares 2 with 2 and finds them equal, and so the *first* tuple wins and (0, 2) is declared the minimum. When using the key function, only the second item of the tuple is looked at; the first item is ignored. So the difference between 0 and -5 is irrelevant, and the tie is decided by which element was seen first. ---------- _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue41276> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com