In these links, you will find more information about the mentioned tools and the official Python documentation for some of the modules that we've discussed:

• This is the official documentation for the BS4 package: http://www.crummy.com/software/BeautifulSoup/bs4/doc
• This is the official documentation for the Scrapy package: http://doc.scrapy.org/en/latest
• This is the official documentation for the mechanize package: http://wwwsearch.sourceforge.net/mechanize
• scrapy commands: https://doc.scrapy.org/en/latest/topics/commands.html
• Comparison between Portia and ParseHub: https://www.parsehub.com/blog/portia-vs-parsehub-comparison-which-alternative-is-the-best-option-for-web-scraping/
• Twint: https://github.com/twintproject/twint