User Input and Output . User Input and output are the core of our application. We want users to be able to add and delete tasks and mark them as completed, failed, or deferred.

A normal Python 3 statement to define an output file looks like: file = open ... And that’s it. A very simple Python application to takes user input and writes it to a file.

Testing functions isn't hard, but how do you test user input and output? In my last article, I started looking at "pytest", a framework for testing Python programs that's really changed the way I look ...