os.path.join("/a","/b")

[Joshua Marshall]

Matthew Dixon Cowles <matt at mondoinfo.com> wrote:
> I was a little surprised today to notice that

> os.path.join("/a","/b") returns '/b'

> (os.path is posixpath in this case of course) while

> os.path.join("/a/","b") returns "/a/b"

> which I expected from both. Poking back into my dusty archives, I find
> that it has been that way since at least 1.4 so I presume that it's a
> feature but I'll be darned if I can figure out the logic. It sure
> doesn't seem to have much to do with joining. The module's docstring
> just says "Join two or more pathname components, inserting '/' as
> needed".

> If someone could explain the logic to me, I'd be grateful.

> Regards,
> Matt

It's as if you cd to directory "/a" and reference "/b".  Since "/b" is
an absolute path, the current directory is ignored.