It is possible that this is easier than I think in Python, but here is an example where Perl made my life (and various co-workers' lives) easier. A couple of years ago I needed to copy a bunch (between 1000 and 2000) posts from an old web site to a new one. This required parsing forms on the destination site, and also stripping out tags the new site did not support. The CPAN module HTML::TreeBuilder allowed me to do this quickly and without undue difficulty.