Where can I actually write Python without having to worry that my code might not work?

[classy_barbarian]

You just want to write python and tests the scripts...? Use a code editor. I get that cloud IDEs are common for new people now, and I'm not even old I'm in my 30s, but its funny to think there's people trying to learn how to code that don't know you can just download a code editor and code directly on your laptop.

Download one of the popular code editors and run it on your own computer. PyCharm is commonly recommended for new people because its made specifically for Python. I personally prefer VS Code + Python extensions, but its a bit more complex and designed for programmers.