A-hunting We Will Go: Debugging pytest with Django
By Cris Ewing

Debugging code is a skill we all must learn, but one that is rarely taught particularly well. We speak about “reading the traceback” as if that alone is sufficient to lead us to the solution to all our problems. But what happens when it isn’t enough? When the traceback is the symptom of a problem that happened elsewhere, or elsewhen? How do you approach debugging when the leads are slim?

This talk presents the tools of debugging couched in a very specific tale of a particular bug hunt. The specific bug is a good one because it presents a number of the classic tough problems in debugging. It starts with an intermittent failure. It has a traceback that is completely remote from the actual cause of the problem. It involves the interaction of three separate systems: a web framework, a test framework, and a database. And in the end, the cause is so small, and the solution so simple, that it serves to remind us all to be humble in the face of the complexity we deal in daily.

During this talk, you'll learn about ways to use printing and logging as well as pdb. You'll see how core Python tools like dbapi2 and the inspect module can help to solve common problems. You'll learn how to spot new avenues for exploration, and how to figure out when you're in a blind alley.

The talk is entertaining for folks of any level, but it’s probably of most use to beginner and intermediate programmers.