Python Testing with pytest

pdb: Debugging Test Failures

The pdb module is the Python debugger in the standard library. You use --pdb to have pytest start a debugging session at the point of failure. Let’s look at pdb in action in the context of the Tasks project.

In ​Parametrizing Fixtures​, we left the Tasks project with a few failures:

$ cd /path/to/code/ch3/c/tasks_proj
$ pytest --tb=no -q
.........................................FF.FFFF
FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF.FFF...........
42 failed, 54 passed in 4.74 seconds

Before we look at how pdb can help us debug this test, let’s take a look at the pytest options available to help speed up debugging test failures, which we first looked at in ​Using Options​:

• --tb=[auto/long/short/line/native/no] ...