Can I use python whit HTML & CSS & JavaScript , how?

Answer 1

flask

Answer 2

Yes, if you run Python code on server side (even with local host), and use it to handle the web server, so you can use it to dynamically answer to web request and send dynamically builded Html/Css/JS...

Look at web sever frameworks modules for Python (Django, Flask, Bottle...) and maybe take a look to live possibilities at pythonanywhere.com ;)