Where can I freely write Python?

My brother in college for a tiny, for fun project had to make a random number game. The computer would choose a random integer between 1 and 10. Then the player had a limited amount of guesses before they would lose. I think I could make this using what I’ve learned in the Python lessons! But where can I freely write the code, and then send him the code?

You can write the code in anything that can write text (even notepad and word), but i would pick something which is a little more designed for coding, like atom

then you can just send the file, but then it requires a python interpreter to run. Services like repl.it might easier, depending what you are looking for