title: How to combine The video and audio files in ffmpeg-python
body: <p>I'm trying to combine a video(with no sound) and its separate audio file </p>
  
  <p>I've tried ffmpeg <code>ffmpeg -i video.mp4 -i audio.mp4 -c copy output.mp4</code>
  and it works fine.</p>
  
  <p>i'm trying to achieve the same output from ffmpeg-python but with no luck. Any help on how to do this?</p>