setting breakpoints with nosetests --pdb option

python testing nose pdb
Devin picture Devin · Feb 9, 2011 · Viewed 22.9k times · Source

nosetests --pdb let's me halt upon error or failure, but this is too late for my needs. Stepping through code during execution helps me debug where the problem is.

However, nosetests are helpful as they allow tests that rely on relative imports (i.e. tests in a package).

How can I set breakpoints before the tests are executed? Currently I'm using:

python -m pdb /path/to/my/nosetests testfile.py

This solution isn't adequate. Nosetests interfere with pdb output, and my keyboard controls (e.g. arrow keys) are broken.

Using import pdb; pdb.set_trace() would seem like a good idea, however nosetests is blocking my access to the pdb console.

Answer

Matt Luongo picture Matt Luongo · Sep 21, 2011

Even better than remembering to use -s is to use the set_trace variant that comes with Nose. Add

from nose.tools import set_trace; set_trace()

wherever you'd like to break in to the debugger. The stdin/out redirection will be taken care of for you. The only strange side effect I've run into is the inability to restart your code from within pdb (using run) while debugging during a nose run.

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