flake8-assertive 2.2.0

Installation

Install from PyPI using pip:

$ pip install flake8-assertive

The extension will be activated automatically by flake8. You can verify that it has been loaded by inspecting the flake8 --version string.

$ flake8 --version
4.0.1 (assertive: 2.1.0, ...) CPython 3.9.10 on Darwin

Error Codes

This extension adds three new error codes (using the A50 prefix):

• A500: prefer {func} for ‘{op}’ comparisons

• A501: prefer {func} for ‘{op}’ expressions

• A502: prefer {func} instead of comparing to {obj}

• A503: use {func} instead of the deprecated {name}

• A504: prefer the ‘msg=’ kwarg for {func} diagnostics

Configuration

Configuration values are specified in the [flake8] section of your config file or as command line arguments (e.g. --assertive-snakecase).

• assertive-snakecase: suggest snake_case assert method names (e.g. assert_true()) instead of the standard names (e.g. assertTrue())

• assertive-test-pattern: fnmatch pattern for identifying unittest test files (and all other files will be skipped)

Caveats

There are some specific cases when the suggestion might not match the intent of the original.

assertIs(a == b, True)

Alternatives

• Teyit is a Python unit test formatter that can perform similar assertion transformations.

2.2.0 (2025-10-11)

• Drop support for Python 3.7, 3.8, and 3.9. Python 3.10+ is now required.

2.1.0 (2022-03-15)

• Suggest using an explicit msg keyword argument with assertTrue() and assertFalse() to avoid accidental two-argument misuse. This is controlled by a new error code: A504

2.0.0 (2021-12-30)

• Drop support for Python 2.7 and 3.6, and add 3.10.

• Drop support for flake8 2.x versions.

1.3.0 (2020-10-12)

• Drop Python version 3.5 support and add version 3.9.

1.2.1 (2019-12-08)

• Support keyword arguments in assert method calls.

1.2.0 (2019-12-05)

• Suggest the preferred names for deprecated methods, such as assertEqual() instead of assertEquals().

1.1.0 (2019-06-26)

• Suggest assertAlmostEqual(a, b, x) for round() expressions like in assertEqual(a, round(b, x)) and assertAlmostEqual(a, round(b, x)) (and similar for assertNotEqual() and assertNotAlmostEqual().

• Recognize assertAmostEquals() and assertNotAlmostEquals() as aliases for assertAlmostEqual() and assertNotAlmostEqual().

• Drop Python 3.4 as a supported version since it has been officially retired.

1.0.1 (2018-07-03)

• Don’t make suggestions for assertions containing multiple comparison operations (e.g. assertTrue(a == b == c)).

1.0.0 (2018-06-04)

• Suggest assertIsNone(a) for assertTrue(a is None), etc.

• Recognize assertEquals() and assertNotEquals() as aliases for assertEqual() and assertNotEqual().

0.9.0 (2018-05-14)

• Initial beta release