So I was thinking about this whole thing, and wondering why it was that seeing things like:
" ".join(aList)
bugged me to no end, while:
aString.lower()
didn't seem to look wrong. I finally put my finger on it, and I haven't seen anyone mention it, so I guess I'll do so. To me, the concept of "join" on a string is just not quite kosher, instead it should be something like this:
aList.join(" ")
or if you want it without the indirection:
['item', 'item', 'item'].join(" ")
Now *THAT* looks right to me. The example of a join method on a string just doesn't quite gel in my head, and I did some thinking and digging, and well, when I pulled up my Smalltalk browser, things like join are done on Collections, not on Strings. You're joining the collection, not the string.
Perhaps in a rush to move some things that were "string related" in the string module into methods on the strings themselves (something I whole-heartedly support), we moved a few too many things there---things that symantically don't really belong as methods on a string object.
How this gets resolved, I don't know... but I know a lot of people have looked at the string methods---and they each keep coming back to 1 or 2 that bug them... and I think it's those that really aren't methods of a string, but instead something that operates with strings, but expects other things.
Boy, are you stirring up a can of worms that we've been through many times before! Nothing you say hasn't been said at least a hundred times before, on this list as well as on c.l.py. The problem is that if you want to make this a method on lists, you'll also have to make it a method on tuples, and on arrays, and on NumPy arrays, and on any user-defined type that implements the sequence protocol... That's just not reasonable to expect. There really seem to be only two possibilities that don't have this problem: (1) make it a built-in, or (2) make it a method on strings. We chose for (2) for uniformity, and to avoid the potention with os.path.join(), which is sometimes imported as a local. If " ".join(L) bugs you, try this: space = " " # This could be a global . . . s = space.join(L) --Guido van Rossum (home page: http://www.python.org/~guido/)