How to wait until operation is completed

[kamrapooja]

We are using ffmpeg python binding to extract audio from given video file. Code sample - try: out, err = (ffmpeg .input(in_filename) .output(out_file, format='s16le', acodec='pcm_s16le', ac=1, ar='16k', ab='160k') .run(capture_stdout=True, capture_stderr=True) ) except ffmpeg.Error as e: print(e.stderr, file=sys.stderr) sys.exit(1) print("hello")

Here hello gets printed before generating the audio file. Is there any way to wait until audio file generation is completed? Please help.