python - How to speed up pytest

Question

Is there some way to speed up the repeated execution of pytest? It seems to spend a lot of time collecting tests, even if I specify which files to execute on the command line. I know it isn't a disk speed issue either since running pyflakes across all the .py files is very fast.

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The various answers represent different ways pytest can be slow. They helped sometimes, did not in others. I'm adding one more answer that explains a common speed problem. But it's not possible to select "The" answer here.

Answer 1

Using the norecursedirs option in pytest.ini or tox.ini can save a lot of collection time, depending on what other files you have in your working directory. My collection time is roughly halved for a suite of 300 tests when I have that in place (0.34s vs 0.64s).

If you're already using tox like I am, you just need to add the following in your tox.ini:

[pytest]
norecursedirs = docs *.egg-info .git appdir .tox

You can also add it in a free-standing pytest.ini file.

The pytest documentation has more details on pytest configuration files.