4.7. 深入 Python 函数定义

def write_multiple_items(file, separator, *args):
    file.write(separator.join(args))

>>> def concat(*args, sep="/"):
...    return sep.join(args)
...
>>> concat("earth", "mars", "venus")
'earth/mars/venus'
>>> concat("earth", "mars", "venus", sep=".")
'earth.mars.venus'