flake8-pytest-style

A flake8 plugin checking common style issues or inconsistencies with pytest-based tests.

Currently the following errors are reported:

| Code | Description | | ------- | ----------- | | [PT001] | use @pytest.fixture over @pytest.fixture()
(configurable by pytest-fixture-no-parentheses) | | [PT002] | configuration for fixture '{name}' specified via positional args, use kwargs | | [PT003] | scope='function' is implied in @pytest.fixture() | | [PT004] | fixture '{name}' does not return anything, add leading underscore | | [PT005] | fixture '{name}' returns a value, remove leading underscore | | [PT006] | wrong name(s) type in @pytest.mark.parametrize, expected {expected_type}
(configurable by pytest-parametrize-names-type) | | [PT007] | wrong values type in @pytest.mark.parametrize, expected {expected_type}
(configurable by pytest-parametrize-values-type and pytest-parametrize-values-row-type) | | [PT008] | use return_value= instead of patching with lambda | | [PT009] | use a regular assert instead of unittest-style '{assertion}' | | [PT010] | set the expected exception in pytest.raises() | | [PT011] | pytest.raises({exception}) is too broad, set the match parameter or use a more specific exception
(configurable by pytest-raises-require-match-for) | | [PT012] | pytest.raises() block should contain a single simple statement | | [PT013] | found incorrect import of pytest, use simple 'import pytest' instead | | [PT014] | found duplicate test cases {indexes} in @pytest.mark.parametrize | | [PT015] | assertion always fails, replace with pytest.fail() | | [PT016] | no message passed to pytest.fail() | | [PT017] | found assertion on exception {name} in except block, use pytest.raises() instead | | [PT018] | assertion should be broken down into multiple parts | | [PT019] | fixture {name} without value is injected as parameter, use @pytest.mark.usefixtures instead | | [PT020] | @pytest.yield_fixture is deprecated, use @pytest.fixture | | [PT021] | use yield instead of request.addfinalizer | | [PT022] | no teardown in fixture {name}, use return instead of yield | | [PT023] | use @pytest.mark.foo over @pytest.mark.foo()
(configurable by pytest-mark-no-parentheses) | | [PT024] | pytest.mark.asyncio is unnecessary for fixtures | | [PT025] | pytest.mark.usefixtures has no effect on fixtures | | [PT026] | useless pytest.mark.usefixtures without parameters | | [PT027] | use pytest.raises() instead of unittest-style '{assertion}' | | [PT028] | test function {name} has default value for argument {arg}, remove it | | [PT029] | set the expected warning in pytest.warns() | | [PT030] | pytest.warns({warning}) is too broad, set the match parameter or use a more specific warning
(configurable by pytest-warns-require-match-for) | | [PT031] | pytest.warns() block should contain a single simple statement |

Installation and usage

As a dependency

Install the plugin using the package manager of your choice, e.g.

uv add --group dev flake8-pytest-style
or
poetry add --group dev flake8-pytest-style
or
pip install flake8-pytest-style

and then run flake8 as you normally would.

As a pre-commit hook

The plugin is a flake8 extension, not a standalone tool. To use it with pre-commit, add the plugin to the additional_dependencies section of the official flake8 hook:

repos:
  - repo: https://github.com/PyCQA/flake8
    rev: 7.3.0
    hooks:
      - id: flake8
        additional_dependencies:
          - flake8-pytest-style==2.2.0

Configuration

The plugin is configured via flake8 configuration file and/or CLI options. Specific errors can be selected or ignored; there are also the following plugin-specific configuration options:

• pytest-fixture-no-parentheses — see [PT001]
• pytest-parametrize-names-type — see [PT006]
• pytest-parametrize-values-type — see [PT007]
• pytest-parametrize-values-row-type — see [PT007]
• pytest-raises-require-match-for — see [PT011]
• pytest-mark-no-parentheses — see [PT023]
• pytest-warns-require-match-for — see [PT030]

For developers

Install deps and setup pre-commit hook

make init

Run linters, autoformat, tests etc.

make format lint test

Bump new version

make bump_major make bump_minor make bump_patch

License

MIT

Change Log

Unreleased

...

2.2.0 - 2025-10-20

• require at least Python 3.10
• support Python 3.14

• support reason= kwarg in pytest.fail for [PT016]
• add [PT028] (checks for default values in test functions)
• add [PT029] (checks for pytest.warns without expected warning)
• add [PT030] (checks for too broad pytest.warns clauses)
• add [PT031] (checks for multiple statements in pytest.warns blocks)
• require at least Python 3.9
• support Python 3.13

• BREAKING: invert default values for pytest-fixture-no-parentheses and pytest-mark-no-parentheses

• require at least Python 3.8.1
• support Python 3.12

• fix false positive for [PT009] on pytest.fail

• update list of unittest-style assert methods for [PT009]/[PT027]

• require at least Python 3.7.2
• support Python 3.11
• add [PT027] (checks for unittest-style assertRaises)

• require at least Python 3.6.2
• expose py.typed file

• better wording for [PT011]
• support Python 3.10

• add [PT025] (checks for erroneous pytest.mark.usefixtures on fixtures)
• add [PT026] (checks for pytest.mark.usefixtures without parameters)

• fix [PT023] not checking marks in classes
• fix [PT004] incorrectly firing on fixtures with yield from

• update flake8-plugin-utils version to improve stability

• fix argparse-related warnings

• add [PT023] (checks for parentheses consistency in pytest.mark usage)
• add [PT024] (checks for unnecessary pytest.mark.asyncio on fixtures)
• fix [PT004], [PT005] firing on abstract fixtures
• fix [PT012] firing on with statements containing a single pass

• add [PT022] (checks for yield fixtures without teardown)

• update flake8-plugin-utils dependency to fix encoding problems on Windows

• fix [PT004]/[PT005] inspecting returns of nested functions

• fix [PT021] for factory fixtures (#46)

• support scoped mocker fixtures from pytest-mock for [PT008]
• check for positional-only lambda arguments in [PT008]
• add [PT020] (checks for pytest.yield_fixture)
• add [PT021] (checks for request.addfinalizer)
• add documentation pages for all rules

• fix [PT011] not reporting match='' as a violation

• add [PT015] (checks for assert False)
• add [PT016] (checks for pytest.fail() without message)
• add [PT017] (checks for assertions on exceptions in except blocks)
• add [PT018] (checks for composite assertions)
• add [PT019] (checks for fixtures without value injected as parameters)

• add [PT014] (checks for duplicate test cases in @pytest.mark.parametrize)

• add configuration option pytest-parametrize-names-type for [PT006]
• add configuration options pytest-parametrize-values-type and

0.5.0 - 2020-03-09

• add configuration option pytest-fixture-no-parentheses for [PT001]
• add [PT013] (checks for from-imports from pytest)

• add [PT012] (checks for multiple statements in with pytest.raises())

• fix default value of pytest-raises-require-match-for config option

• add [PT010] and [PT011] (checks for pytest.raises parameters)

• add [PT009] (ported from flake8-pytest)

• add yield fixtures support
• fix changelog entry for 0.1.2

• fix parametrize checkers not working in decorators

• update PyPI description

• initial