从字符串到毫秒：
s = "4:34.234"hours, minutes, seconds = (["0", "0"] + s.split(":"))[-3:]hours = int(hours)minutes = int(minutes)seconds = float(seconds)miliseconds = int(3600000 * hours + 60000 * minutes + 1000 * seconds)从毫厘到字符串：
hours, milliseconds = divmod(miliseconds, 3600000)minutes, milliseconds = divmod(miliseconds, 60000)seconds = float(milliseconds) / 1000s = "%i:%02i:%06.3f" % (hours, minutes, seconds)
