Passing python_files option to pytest.Config

[ktbarrett]

I support a Python-based HDL testing framework cocotb where we use pytest's assertion rewriting like so.

# Install the assertion rewriting hook, which must be done before we
# import the test modules.
from _pytest.assertion import install_importhook
from _pytest.config import Config

pytest_conf = Config.fromdictargs({}, ["--capture=no"])
install_importhook(pytest_conf)

However, this only applies assertion rewriting to modules that match test_*.py, which many users find a little annoying seeing as our current system has the user specify the test modules manually. The python_files config option seems to do what I want (tested by putting it in a pytest.ini file), but passing it to the Config constructor doesn't seem to work. The test for this option all write out an ini file so is python_files somehow a "config file only" option, or am I missing something?

# What I tried
Config.fromdictargs({"python_files": "*.py"}, ["--capture=no"])

[nicoddemus]

Hi @ktbarrett sorry for the delay.

Any config option can be passed via command-line using -o, for example pytest -o python_files=*.py.

See the starting paragraph of Configuration Options.

Hope that helps!

[ktbarrett]

I tried the following based on your response and assertion rewriting occured, thanks!

pytest_conf = Config.fromdictargs({}, ["--capture=no", "-o", "python_files=*.py"])
install_importhook(pytest_conf)

As a matter of curiosity, what's the intended way to use the option_dict argument in Config.fromdictargs?

[RonnyPfannschmidt]

its a "broken" hack thats there for pytest-xdist - unfortunately its a larger refactoring to fix it

bascially its supposed to be possible to pass python-files inside of that, but its not working

[ktbarrett]

One more follow on question. How do you specify multiple python_files on the command line? I tried to follow the documentation's example of separating the elements with a space like Config.fromdictargs({}, ["--capture=no", "-o", "python_files='a.py b.py'"]), but that does not seem to work. Neither does separating the elements with commas.

EDIT: nvm, it seemed not to like using the quotation marks when there were multiple elements ('a.py b.py'), but was fine with them with one element ('a.py') which led me astray. Space separated like so works (python_files=a.py b.py).