"failure to load referenced CSS or image files" -- is there a way for bots (in particular, mechanize in perl/python) to also download those files? Very much so

"failure to load referenced CSS or image files" -- is there a way for bots (in particular, mechanize in perl/python) to also download those files? Very much so, after all your browser does without you having to tell it to do so. It all depends on whether the hassle is worth it for the bot writer.