如何使用python自动浏览？

suppose, I need to perform a set of procedure on a particular website say, fill some forms, click submit button, send the data back to server, receive the response, again do something based on the response and send the data back to the server of the website. I know there is a webbrowser module in python, but I want to do this without invoking any web browser. It hast to be a pure script.suppose, I need to perform a set of procedure o