Soup Sieve is a CSS selector library designed to be used with 
Beautiful Soup 4. It aims to provide selecting, matching, and 
filtering using modern CSS selectors.

Soup Sieve >= 2.0.0 has dropped Python 2 support. The
python-soupsieve SlackBuild is available at version 1.9.6.

Soup Sieve >= 2.9 does not support more Python 3.9, so this is
the lastest version compatible with Slackware 15.0.

python3-build, python3-hatchling, python3-installer are
dependencies required for the build only.

Finally Soup Sieve is a circular dependency that requires
Beautiful Soup 4 in runtime, so build and installation of
Beautiful Soup 4 is strongly recommended after python3-soupsieve.