Python convert duration in seconds to hh:mm:ss:ms

[LeeJacek]

Hi. I want read audio file duration in hh:mm:ss:ms, so i use mutagen and i obtain duration time in seconds. Next i try convert it to final format but i have error ValueError: Invalid format string.

import mutagen
import random
import time
import sys
import mad
from datetime import datetime
from mutagen.mp3 import MP3
import glob,os
audio = MP3("example.mp3")
len = time.strftime('%H:%M:%S.%f', time.gmtime(audio.info.length))
print (len)enter code here