def addpackage(sitedir, name, known_paths):
    """Process a .pth file within the site-packages directory:
       For each line in the file, either combine it with sitedir to a path
       and add that to known_paths, or execute it if it starts with 'import '.
    """
    if known_paths is None:
        known_paths = _init_pathinfo()
        reset = True
    else:
        reset = False
    fullname = os.path.join(sitedir, name)
    print(fullname)
    try:
        f = open(fullname, "r")
    except OSError:
        return
    with f:
        for n, line in enumerate(f):