How to Debug in Python Without Going Crazy

You’re feeling pretty good about yourself. You’ve been learning Python and you’re finally comfortable enough with your skills to put together a full-on program. It was a lot of work, but you put the code together and wrote the app. And… it doesn’t work. Having broken code is a song every programmer can sing by heart, and it’s a big part of the development process. Learning to debug in Python is crucial to increasing your skills and finding success.

We’ve gathered some important tips to guide you through the Python debugging process. In this guide, we give you the tools you need to transform debugging from a daunting chore to an integral skill set that makes you an effective programmer. We show you how to get the most out of Python’s powerful debugging commands, and we make some key recommendations on best practices to streamline the code-repair process. With our help, you’ll soon be squashing bugs with the best of them!

Know Your Python Debug Commands

The advantage of debugging is that it lets you walk through the program step by step until you discover the problem. A big part of effective debugging (and of life in general) consists simply of knowing what to say to get the information you need. Many developers have spent countless hours banging their heads against the wall trying to get a program to behave because they didn’t have the right vocabulary to find out what was wrong with it. That’s why you need to have a solid grasp of Python’s debugging commands in order to pinpoint issues quickly and correctly.

When working with Python, the “pdb” command is your best friend. It’s a command-line utility that has all of the features you’ll need to debug your program, and it’s beautiful in its simplicity. Once you enter “pdb” at the point in the program you wish to examine, you can use the “list” command to view the specific Python code lines and navigate through them using up (“p”) and down (“d”), as well as step (“s”) and next (“n”). The Python Software Foundation maintains Python’s manuals and keeps them current—bookmark the debug command page to use as a reference.

Start Small with the Print Command

There are times when you might be able to avoid diving headfirst into the Python debugger. If you can fix your code without resorting to debugging, you can speed up your coding process and get a finished product out the door without a lot of fuss. That’s why it’s always worth giving the “print” command a try before bringing out the big guns.

You can use “print” to view the raw Python code. While that might seem daunting at first, you’ll soon get used to scanning vast reams of coding language and identifying the areas that just don’t look right. Remember the guy in The Matrix who could look at the code and see blondes, brunettes, and redheads? That’ll be you only, instead of beautiful people, you’ll see button functions and database calls. It’s not as glamorous as what ol’ Cypher saw, but it’ll make you a crackerjack programmer.

While the thought of debugging might fill you with dread and make you break out in a sweaty panic, a well-practiced debug process is a key aspect to a well-rounded programmer. Employers will value your debugging skills, and your coworkers will appreciate you for handing off clean code. It’s easy to debug once you get the hang of it, and our guide can help you get started. Code away, and have fun chasing any little bugs you might encounter on your journey!