expand_path.py

def expand_path(path, absolute=False, max_loop=10):

    for loop in range(max_loop):
        newpath = os.path.expandvars(path)
        newpath = os.path.expanduser(newpath)

        if newpath == path:
            break
        else:
            path = newpath

    if absolute:
        path = os.path.abspath(path)

    return path