How to input into a webpage

i want to put input into a web page say for example auto-login to a website so the python program would open the web page and input the user and password automatically into the web page and press the login button automatically. how would that be possible.

i want to make a program which i can automatically login into a web page.

import webbrowser

webbrowser.open('https://m.facebook.com/login/?locale2=en_GB')

//i have the basics of opening this page but now i want to do an input.

the program would open the page and then input email and password then press the login button automatically.