Show and set the CatalogURL on macOS 10.10 and greater

catalogUtilities.py

#!/usr/bin/python

import objc

from Foundation import NSBundle, NSClassFromString

SeedingBundle = NSBundle.bundleWithPath_('/System/Library/PrivateFrameworks/Seeding.framework')

functions = [
             ('currentCatalog', '@'),
             ('_setCatalog', b'@*'),
            ]
            
objc.loadBundleFunctions(SeedingBundle, globals(), functions)
catalogUtilities = NSClassFromString('SDCatalogUtilities')

# show CatalogURL
print "CatalogURL: %s" % catalogUtilities._currentCatalog()

# change CatalogURL
catalogUtilities._setCatalog_("https://swscan.apple.com/content/catalogs/others/index-10.13seed-10.13-10.12-10.11-10.10-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog.gz")

# show changed CatalogURL
print "CatalogURL: %s" % catalogUtilities._currentCatalog()