TopolearnShared configuration means local runs and CI use identical options, paths and rules.
pytest reads configuration from the first of pytest.toml, pytest.ini, pyproject.toml, tox.ini or setup.cfg that has a pytest section, searching from the common ancestor of the given paths upward. Its directory becomes the rootdir, used for node ids and the cache.
In pyproject.toml, pytest 9 reads a native [tool.pytest] table with real TOML types; the older [tool.pytest.ini_options] table with ini-style values still works and is what you'll see in most existing projects.
Options worth setting in every project:
testpaths = ["tests"]: where to look when you run barepytest, which speeds up collection.addopts: default flags, e.g.["-ra", "--strict-markers"].markers: register custom markers with descriptions.strict = true(pytest 9): turns on strict config, strict markers, strict xfail and strict parametrize ids together.filterwarnings = ["error"]: turn warnings into errors, with exceptions for noisy third-party ones.minversion/required_pluginsto fail fast in a misconfigured environment.pythonpath = ["src"]if you don't install the package.
Any option can be overridden for a single run with -o name=value. pytest --help lists every configuration key, including those added by plugins, at the bottom.
Example
# pyproject.toml (pytest 9 native TOML table)
[tool.pytest]
minversion = "9.0"
testpaths = ["tests"]
addopts = ["-ra"]
strict = true
markers = [
"slow: long-running tests (deselect with -m 'not slow')",
"integration: needs external services",
]
filterwarnings = [
"error",
"ignore::DeprecationWarning:somelib.*",
]
# Older equivalent, still supported:
# [tool.pytest.ini_options]
# testpaths = ["tests"]
# addopts = "-ra --strict-markers"Remember
- Configuration lives in pytest.toml, pytest.ini or pyproject.toml
- pytest 9 supports a native [tool.pytest] table; ini_options still works
- Set testpaths, addopts, markers and strictness
- filterwarnings = ['error'] catches deprecations early
Watch out for
- Having both pytest.ini and a pyproject section and editing the one pytest ignores.