On Mon, Mar 7, 2011 at 4:32 AM, Mart Sõmermaa <mrts.pydev@gmail.com> wrote:
However, I myself, the Ruby folks and Nick would rather emphasize the "zero-element-nature" [1] of ''.
I did say maybe. As Jesse notes, there's another pattern based line of argument that goes: len(',,'.split('.')) == 3 len(','.split('.')) == 2 len(''.split('.')) == ??? (Well, 1 "obviously", since the pattern suggests that even when there is no other text in the string, the length of the split result is always 1 more than the number of separators occurring in the string) There are reasonable arguments for "''.split(sep)" as the inverse of either "sep.join([''])" or "sep.join([])", but once *either* has been chosen for a given language, none of the arguments are strong enough to justify switching to the other behaviour. Note that, independent of which is chosen, the following identity will hold for an explicit separator: sep.join((text.split(sep)) == text It's only composing them the other way around as "sep.join(data).split(sep)" that will convert either [] to [''] (as in Python) or [''] to [] (as in Ruby). Cheers, Nick. -- Nick Coghlan | ncoghlan@gmail.com | Brisbane, Australia