Takes directory paths as command line arguments and then for each directory prints all files not present in any of the other directories. Bython will ignore file extensions and therefore only compare the basename of each file.
python3 bython.py folder/1 folder/2 folder/3 ...
Assuming you have the following directory layout
folder/1
|-- 1.MP4
|-- 2.MP4
|-- 3.MP4
folder/2
|-- 1.MP4
|-- 2.MP4
|-- 4.MP4
folder/3
|-- 1.MP3
|-- 2.MP3
|-- 4.MP3
You will get
File 3 is in files/1 but not in files/2
File 3 is in files/1 but not in files/3
File 4 is in files/2 but not in files/1
File 4 is in files/3 but not in files/1