Registry / testing / flake8-string-format

flake8-string-format

library0.4.0pypypiunverified

An extension for Flake8 that enforces best practices for `str.format` usage. It identifies various issues such as unindexed parameters, insufficient arguments in format calls, mixed implicit and explicit indexing, and unused arguments. The current version, 0.3.0, was released in February 2020, indicating a maintenance release cadence focusing on stability rather than frequent updates.

testing

pip install flake8 flake8-string-format

github ↗package ↗

INSTALL

IMPORT

SIG · FLAKE8-STRING-FORM

flake8-string-format

testingpythonv0.4.0

Install

1.8s avg

Import

—

Disk

17MB

Pass rate

10/ 10

Env Coverage10 / 10

glibc

3.9–3.13

musl

3.9–3.13

Install & Compatibility

Where this runs

tested against v0.4.0 · pip install

no network on importno background threads

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

py 3.10–3.920 runs

installs and imports cleanly · install 0.0s · import 0.000s · 19.3MB

glibc

py 3.10–3.920 runs

installs and imports cleanly · install 1.8s · import 0.000s · 20MB

17MB installed

● package 17MB

Code

Verified usage

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

flake8-string-format

✓ No direct import is typically needed. Flake8 plugins are automatically discovered upon installation.

Users do not import this library directly into their Python code. It extends the functionality of the 'flake8' command-line tool.

After installation, `flake8-string-format` automatically integrates with Flake8. Simply run `flake8` on your project. The plugin will report errors using codes like P101 (unindexed parameters), P201 (missing arguments), and P301 (unused arguments). Errors can be ignored using the `--ignore` flag or by configuring your `.flake8` file.

# my_module.py def example_function(): message = 'Hello {}'.format('World') # P101: format string does contain unindexed parameters data = {'name': 'Alice'} greeting = 'Hello {name}'.format(**data) # The plugin checks string formatting. To run: # flake8 my_module.py # To ignore a specific error: # flake8 --ignore P101 my_module.py

flake8 --version

Debug

Known issues

breakingVersion 0.3.0 removed support for running `flake8-string-format` as a standalone tool. It must now be used exclusively as a plugin for Flake8.

fix

Ensure `flake8` is installed and run the checks using the `flake8` command-line tool.

affects: 0.3.0 and later

gotchaPython 2.6 support is partial. The plugin may not detect implicit parameters as errors (P1XX) on Python 2.6, but might still report P301 if variable arguments are unused.

fix

For full compatibility checks and consistent behavior, use Python 2.7+ or Python 3. For Python 2.6, be aware of the limitations regarding implicit parameter detection.

affects: All versions

gotchaError codes P102 ('docstring does contain unindexed parameters') and P103 ('other string does contain unindexed parameters') are prone to false positives and are generally recommended only for Python 2.6 projects where unindexed parameters are strictly forbidden.

fix

Consider ignoring P102 and P103 by default using `--ignore P102,P103` in your `flake8` configuration, unless your project specifically targets Python 2.6 with a strict no-unindexed-parameters policy for all strings.

affects: All versions

Upgrade

Version history

0.4.0latest on PyPI · released Jun 9, 2026

Audit

Dependencies

flake8requiredThis library is a plugin for Flake8 and requires it to function.

Agent activity

11 hits · last 30 days

node

Amazon

Resources

githubhttps://github.com/xZise/flake8-string-format ↗

packagehttps://pypi.org/project/flake8-string-format/ ↗