Web scraping is harvesting data from websites through either an API or a page's web browser. The point of web scraping is to collect an enormous amount of information relatively easily and quickly. It works by:
Tweepy Tutorial
Python, Data Science, Text Analytics blog by Marco Bonzanini
Beautiful Soup Guides
Twitter scraper tutorial with Python by Randy Daw-Ran Liou
Beginner's Guide to Collecting Twitter data by Allen Zen
Guides from Twitter
Webscraping Guide
Research Guide from Temple University