I have a problem with Pydub module running in Windows and Linux. When I try open a mp3 file thus:
from pydub import AudioSegment
sound = AudioSegment.from_mp
Make sure that you have ffmpeg http://www.ffmpeg.org/ installed. You can get help from this official page.
Other thing that I can think of is that ffmpeg is installed and is in your path but not in the path of the process using pydub.
If this is the reason for the error, then you can set the absolute path to ffmpeg directly like shown below:
import pydub
pydub.AudioSegment.ffmpeg = "/absolute/path/to/ffmpeg"
sound = AudioSegment.from_mp3("test.mp3")
Give this a try.