replace dash by space in pytest's report - python-3.x

Question

I'm on my way to simplify a set of tests by pytest by stacking parameters
import pytest
#pytest.mark.parametrize("option_a", ["-r", "-s"])
#pytest.mark.parametrize("option_b", ["--alpha", "--beta", "--gamma"])
def test_foo(option_a, option_b):
assert option_a in ["-r", "-s"]
As anticipated, the above MWE performs an exhaustive permutation:
======================================= test session starts =======================================
platform linux -- Python 3.9.7, pytest-6.2.4, py-1.10.0, pluggy-0.13.1 -- /usr/bin/python3
cachedir: .pytest_cache
rootdir: /home/guest/Desktop/project, configfile: pytest.ini
collected 6 items
test_ping.py::test_foo[--alpha--r] PASSED [ 16%]
test_ping.py::test_foo[--alpha--s] PASSED [ 33%]
test_ping.py::test_foo[--beta--r] PASSED [ 50%]
test_ping.py::test_foo[--beta--s] PASSED [ 66%]
test_ping.py::test_foo[--gamma--r] PASSED [ 83%]
test_ping.py::test_foo[--gamma--s] PASSED [100%]
======================================== 6 passed in 0.02s ========================================
What bothers me a bit is the additional dash trailing the first parameter (--alpha, --beta, --gamma). Someone not familiar enough with pytest may assume the second parameter tested would be --r (instead of -r), or --s (instead of -s).
Is there a practical approach to substitute this separator by a blank space? Since this is just an issue how output to the CLI is formatted, I would like to refrain to define multiple fixtures for each test function.

Answer 1

To summarize our comments, it's possible to use ids and keep in mind test ordering. pytest is going to use the parameter with the higher number of levels as an outer loop (here: option_b), the one with fewer levels as the inner one (here: option_a). Also, I have added the custom_format function as an example of an approach how to custom a view of a parameter.
import pytest
#pytest.mark.parametrize("option_a", ["-r", "-s"], ids=[" -r", " -s"])
#pytest.mark.parametrize("option_b", ["--alpha", "--beta", "--gamma"], ids=["--alpha ", "--beta ", "--gamma "])
def test_foo(option_a, option_b):
assert option_a in ["-r", "-s"]
def custom_format(val):
return f" {val} "
#pytest.mark.parametrize("option_a", ["-r", "-s"], ids=custom_format)
#pytest.mark.parametrize("option_b", ["--alpha", "--beta", "--gamma"], ids=custom_format)
def test_foo_1(option_a, option_b):
assert option_a in ["-r", "-s"]
It will not remove hyphens between parameters but could decrease confusion.
collected 12 items
test_.py::test_foo[--alpha - -r] PASSED [ 8%]
test_.py::test_foo[--alpha - -s] PASSED [ 16%]
test_.py::test_foo[--beta - -r] PASSED [ 25%]
test_.py::test_foo[--beta - -s] PASSED [ 33%]
test_.py::test_foo[--gamma - -r] PASSED [ 41%]
test_.py::test_foo[--gamma - -s] PASSED [ 50%]
test_.py::test_foo_1[ --alpha - -r ] PASSED [ 58%]
test_.py::test_foo_1[ --alpha - -s ] PASSED [ 66%]
test_.py::test_foo_1[ --beta - -r ] PASSED [ 75%]
test_.py::test_foo_1[ --beta - -s ] PASSED [ 83%]
test_.py::test_foo_1[ --gamma - -r ] PASSED [ 91%]
test_.py::test_foo_1[ --gamma - -s ] PASSED [100%]