Sometimes you might need to create an account and log in to access the information and data extraction you need.
If you have a good HTTP library that handles logins and automatically sends session cookies (did I mention how awesome Requests is?), then you just need to log in before it gets to work.
In many scenarios, the data is available after login that you want to scrape.
So to reach at the page where data is located you need to implement code in web scraper that automatically takes username/email and
password to login into a website, once the login is done you can do crawling and parsing as required.
We often have to write spiders that need to log in to sites, in order to data extraction from them.
Our customers provide us with the site, username and password, and we do the rest.