Practical Debugging - Tips, Tricks and Ways to Think

Discover practical debugging techniques, tips, and strategies in this 40-minute EuroPython Conference talk by Radoslav Georgiev. Learn how to approach common debugging scenarios, including troubleshooting tutorial issues, identifying unexpected feature breaks, and handling third-party library problems. Explore critical changes, binary search, problem isolation, interactive debuggers, printing, testing, and greping techniques. Gain insights into generalizing debugging skills and handling situations where bugs seem unsolvable. Through real-world examples in Python, master the art of effective debugging and enhance your problem-solving abilities as a developer.

Syllabus

Intro
Goal of this talk
There's an exception. Example: Text file with datetime intervals & python program that checks if there are any overlapping
Stack trace is a friend!
Now, lets run.
Debugger time!
ipdb/pdb • Interactive python debugger
Fixing the funciton
Test are passing. Lets try real world!
launch_ipdb_on_exception
Fix, tests passing, all good
Exception types Sometimes, the library or framework is going to tell you that you messed up
Nothing's happening!
Do the detective work. . You are in the dark and you need to find a source of light to guide you
Break it on purpose & try to get an exception
Code isolation is your friend
Common gothas
An example
Binary search debugging
Are your tests OK?
Do you need validation?
Is your algo OK? Are you using external library? Have you implemented
Do you understand the problem space well enough? You may be solving the wrong thing.
Explain your problem to someone
Parallel debugging