Some websites don’t like to be scraped. In these cases you may need to simulate a real user working with a browser. Selenium launches and controls a web browser.
from selenium import webdriver
browser = webdriver.Firefox() # launch firefox browser
browser.get('http://stackoverflow.com/questions?sort=votes') # load url
title = browser.find_element_by_css_selector('h1').text # page title (first h1 element)
questions = browser.find_elements_by_css_selector('.question-summary') # question list
for question in questions: # iterate over questions
question_title = question.find_element_by_css_selector('.summary h3 a').text
question_excerpt = question.find_element_by_css_selector('.summary .excerpt').text
question_vote = question.find_element_by_css_selector('.stats .vote .votes .vote-count-post').text
print "%s\n%s\n%s votes\n-----------\n" % (question_title, question_excerpt, question_vote)
Selenium can do much more. It can modify browser’s cookies, fill in forms, simulate mouse clicks, take screenshots of web pages, and run custom JavaScript.