Registry / testing / parametrize-from-file

parametrize-from-file

library0.21.0pypypi✓ verified 83d ago

A pytest plugin that allows parametrizing test functions with values read from external config files (JSON, TOML, YAML, INI, etc.). Version 0.21.0 supports Python ~=3.8. Releases are infrequent, typically a few times per year.

testing

pip install parametrize-from-file

github ↗package ↗docs ↗

INSTALL

IMPORT

SIG · PARAMETRIZE-FROM-F

parametrize-from-file

testingpythonv0.21.0

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

parametrize_from_file

✓ import parametrize_from_file

✗ from parametrize_from_file import parametrize_from_file

The module exports a top-level function with the same name as the package.

parametrize_from_file.add_source

✓ from parametrize_from_file import add_source

✗ import parametrize_from_file.add_source

add_source is a function, not a submodule.

The decorator loads parameters from a file named after the test module (e.g., test_*.yaml). The file is expected in the same directory as the test file.

import parametrize_from_file @parametrize_from_file @pytest.mark.parametrize("x, expected", [ (1, 2), (2, 4), ]) def test_double(x, expected): assert x * 2 == expected

Debug

Known issues

breakingIn v0.20.0, the default config format changed from YAML to JSON. Existing YAML test data files will not be found unless you specify the format explicitly.

fix

Use @parametrize_from_file(format='yaml') or rename/convert files to JSON.

affects: >=0.20.0

gotchaThe decorator must be applied BEFORE @pytest.mark.parametrize. If applied after, parametrize_from_file will not be able to intercept the parametrization.

fix

Ensure @parametrize_from_file is the outermost decorator (i.e., directly above the test function, below any @pytest.mark.*).

affects: all

deprecatedThe 'parametrize_from_file.add_source' function was deprecated in v0.18.0 and will be removed in a future release.

fix

Use @parametrize_from_file(source='...') instead.

affects: >=0.18.0

Errors

Common errors & fixes

pytest: error: unrecognized arguments: --parametrize-from-file-format

Using the command-line option for an older version that was removed in v0.20.0.

fix

Remove the --parametrize-from-file-format argument and specify format within the decorator: @parametrize_from_file(format='yaml').

TypeError: parametrize_from_file() missing 1 required positional argument: 'params'

Using the decorator without parentheses when no extra arguments are needed.

fix

Use @parametrize_from_file() with parentheses, even if no arguments are passed.

pytest.fail.Exception: Could not find a test data file for test_my_func

The default file name does not match the test function name (e.g., test file is 'data.yaml' but expects 'test_my_func.yaml').

fix

Specify the file explicitly: @parametrize_from_file(source='data.yaml').

Upgrade

Version history

0.21.0latest on PyPI · released May 1, 2026

Audit

Dependencies

No dependency data recorded yet.

Agent activity

2 hits · last 30 days

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Resources

githubhttps://github.com/kalekundert/parametrize_from_file ↗

packagehttps://pypi.org/project/parametrize-from-file/ ↗

docshttps://parametrize-from-file.readthedocs.io/en/latest/ ↗