Python - Some concepts used in Scrapy, BeautifulSoup, Mechanize

Reference:
CSS - https://www.w3schools.com/css/default.asp
XPath - https://www.w3schools.com/xml/xpath_intro.asp
yield - https://stackoverflow.com/questions/231767/what-does-the-yield-keyword-do

Example -  https://www.digitalocean.com/community/tutorials/how-to-scrape-web-pages-with-beautiful-soup-and-python-3

Module "Mechanize"documentation - http://wwwsearch.sourceforge.net/mechanize/faq.html (Python 3 is not yet supported)