Jeff> For those that prefer not to add functions all willy-nilly, would Jeff> it not be better to add a "delimiter" keyword that defaults to Jeff> False? Then "delimiter=False" will function with the current Jeff> functionality unchanged while
Jeff> os.path.commonprefix(["bob/export/home", "bob/etc/passwd"], delimiter = "/")
Jeff> would properly return
Jeff> 'bob/'
On Windows what would you do with this crazy, but valid, path?
c:/etc\passwd
I don't do Windows, so don't have any idea if there is even an /etc/passwd file on Windows. I'd guess not, but that's not the point. The point is that you can use both / (aka ntpath.sep) and \ (aka ntpath.altsep) in Windows pathnames. See my patch (issue 4755) for a version of os.path.<whatever> which works as at least I expect and should work cross-platform.
Skip