Rewritting https://gitlab.cern.ch/atlas/athena/blob/master/Trigger/TrigValidation/TrigValTools/bin/check_log.pl in Python, as nobody uses Perl anymore.
Was checked in here! https://gitlab.cern.ch/atlas/athena/-/commit/c94d618fa3effc5e5e400755c853079aecefe682 (Stewart Martin-Haugh was my supervisor!)