Debugging techniques

In this part, we'll introduce you to some of the techniques we use most often. This is not an exhaustive list, but it should give you some useful ideas for where to start when debugging your own Python code.

Debugging with print

The key to understanding any bug is to understand what your code is doing at the point where the bug occurs. For this reason, we'll be looking at a few different techniques for inspecting the state of a program while it is running.

Probably the easiest technique of all is to add print() calls at various points in your code. This allows you to easily see which parts of your code are executed, and what the values of key variables are at different points during execution. For example, if you are developing a Django website and what happens on a page is not what you would expect, you can fill the view with prints and keep an eye on the console while you reload the page.

There are several drawbacks and limitations...