unable to overwrite audio

[xuloo]

I've been assuming the following code:

video = VideoFileClip("video.mp4")
audio = AudioFileClip("audio.m4a")
video.set_audio(audio)
video.write_videofile("output.mp4")

should output a video file with the audio track assigned from the audio.m4a file - but it doesn't i only ever just get a copy of video.mp4 with no audio.

What am i doing incorrectly here? can i overwrite audio at all?

[xuloo]

ok, so seconds after posting this i re-read the manual and i see that set_audio() returns a copy of the original video with the audio set.... so that's my fix.

Apologies for not RTFM'ing more closely :)