Is there an option to split to volumes?

[CelebStalker]

Can someone help with the code for the GUI?

[miurahr]

You can find a manual explanation of multi-volume at
https://py7zr.readthedocs.io/en/latest/user_guide.html#extraction-from-multi-volume-archive

If you want to create multi volume archive using multivolumefile library, following example do it for you.

import multivolumefile
import py7zr

target = pathlib.Path('/target/directory/')
with multivolumefile.open('example.7z', mode='wb', volume_size=10240) as target_archive:
    with SevenZipFile(target_archive, 'w') as archive:
        archive.writeall(target, 'target')