There are some pieces of code that have a million little details that you get wrong while developing. The workflow becomes: write some code, run, fix some trivial error, run, fix another trivial error, run, fix, run, fix, ad nauseum.
For these things it helps to get immediate feedback, so I wrote PythonAsYouType which runs your code for every keystroke and gives you any printed output in realtime. Of course there are some limitations, like the code you are working on needs to be fairly fast to execute or it becomes annoying. To alleviate this there’s a field to do any heavy setup you might have up front like reading files, etc.
You have to try it to really understand how it can change some problems from boring and annoying to just a joy to code.