What's the easiest Python library to use to extract properties from an AAC audio file (.m4a)?
Specifically, I'd like to extract the following properties:

Sample rate
Channel count (mono or stereo)
Length (in seconds)
Try using the command exiftool. Of course, if you're using linux. This command shows all the properties of audio files, video and pictures. Exiftool installed, simply use the command:
exiftoll your_file_name.extension
eg
exiftoll music.mp3
Extract AAC audio properties using Python?