Le Wed, 15 Apr 2009 11:17:07 -0700, "Raymond Hettinger" firstname.lastname@example.org s'exprima ainsi:
I propose adding a "default" keyword argument to max() and min(), which provides a value to return in the event that an empty iterable is passed.
Could you write your proposal out in pure python so we can see how it interacts with the key-keyword argument and how it works when the number of positional arguments is not one.
Will min(default=0) still return a TypeError? Will min(1, 2, default=0) return 0 or 1? Will min([1,2], default=0) return 1? # different from min([0,1,2])
While there has been quick support for the proposal, I do not find it as obvious as it seems. I see an issue based on a possible confusion about "default". Actually, "default" is the name of a proposed optional argument for min() and max() -- but this does not mean this argument, that happens to be called "default", itself has an evident default value ;-) Even for min(), I really doubt 0 is a right choice as "default"'s default value; while for max() it's imo obviously wrong.
The issue as I see it is related to the fact that python does not allow optional arguments without default values -- which in most cases is not problematic. But here I would like an hypothetical min(s, optional default) or min(s, ?default)
While this is not possible, I support the proposal with None as default value for "default", instead of an often wrong choice. min(s, default=None) max(s, default=None)
Maybe another word as "default" would help avoid confusion, too.
Denis ------ la vita e estrany