list packages that were in CentOS 9 that are not in CentOS 10

removed-in-c10.py

#!/usr/bin/python3

import json
from urllib.request import urlopen


def get_pkgs(compose_url):
    rpms_url = compose_url + 'compose/metadata/rpms.json'
    with urlopen(rpms_url) as response:
        data = json.loads(response.read())
    return {
        # convert name-epoch:version-release.arch key to just the name
        nevra.rsplit('.', maxsplit=1)[0].rsplit('-', maxsplit=2)[0]
        # only packages from these repos are forbidden in epel
        for repo in ['BaseOS', 'AppStream', 'CRB']
        for arch in data['payload']['rpms'][repo].keys()
        for nevra in data['payload']['rpms'][repo][arch].keys()
    }

pkgs_c9 = get_pkgs('https://composes.stream.centos.org/production/latest-CentOS-Stream/')
pkgs_c10 = get_pkgs('https://composes.stream.centos.org/stream-10/production/latest-CentOS-Stream/')

# packages that were in CentOS 9 but not are not in CentOS 10
results = sorted(pkgs_c9 - pkgs_c10)
print('\n'.join(results))