Following symlinks in Python

Today's Python trivia question: you have the path of a symbolic link. How do you get the full destination that link points to? If your answer is "use os.readlink", well it's not quite that easy. I'm not alone in finding the docs here confusing when they say: "the result may be either an absolute or relative pathname" and then only tell you how to interpret the result if it's relative. This guy wonders the same thing I did, which is how to know whether the returned value is a relative or absolute path?

I found a clue as to the way to handle both cases in the PathModule code, which is that you use os.path.isabs on the result to figure out what you got back. That module is a lot of baggage to pull in if you just want to correct this one issue, though, so here's a simpler function that knows how to handle both cases:

def readlinkabs(l):
    """
    Return an absolute path for the destination 
    of a symlink
    """
    assert (os.path.islink(l))
    p = os.readlink(l)
    if os.path.isabs(p):
        return p
    return os.path.join(os.path.dirname(l), p)

I hope my search engine cred bubbles me up so someone else trying to look this up like I did doesn't have to bother reinventing this particular tiny wheel.