Can I write Python in react?

Yes . React is mostly agnostic of what’s going on at the server-level. ie it does not care what backend you use.

In this article, we will learn how to run a Python script in HTML.

How to Run a Python script from Node.

You cannot directly invoke a Python function from JS : JS is executed in your browser; Python is executed in your server. In order to call a Python function (in your server) from JS (in your browser), you need an interaction from the browser to the server.