The Flake8 Python linter (https://flake8.pycqa.org/).

Backend: pants.backend.python.lint.flake8
Config section: [flake8]

Basic options

skip

--[no-]flake8-skip

PANTS_FLAKE8_SKIP

default: False

If true, don't use Flake8 when running ./pants lint.


args

--flake8-args="[<shell_str>, <shell_str>, ...]"

PANTS_FLAKE8_ARGS

default: []

Arguments to pass directly to Flake8, e.g. --flake8-args='--ignore E123,W456 --enable-extensions H111'.


export

--[no-]flake8-export

PANTS_FLAKE8_EXPORT

default: True

If true, export a virtual environment with Flake8 when running ./pants export.

This can be useful, for example, with IDE integrations to point your editor to the tool's binary.


Advanced options

version

--flake8-version=<str>

PANTS_FLAKE8_VERSION

default: flake8>=3.9.2,<4.0

Requirement string for the tool.


extra_requirements

--flake8-extra-requirements="['<str>', '<str>', ...]"

PANTS_FLAKE8_EXTRA_REQUIREMENTS

default: []

Any additional requirement strings to use with the tool. This is useful if the tool allows you to install plugins or if you need to constrain a dependency to a certain version.


lockfile

--flake8-lockfile=<str>

PANTS_FLAKE8_LOCKFILE

default: <default>

Path to a lockfile used for installing the tool.

Set to the string <default> to use a lockfile provided by Pants, so long as you have not changed the --version and --extra-requirements options, and the tool's interpreter constraints are compatible with the default. Pants will error or warn if the lockfile is not compatible (controlled by [python].invalid_lockfile_behavior). See https://github.com/pantsbuild/pants/blob/release_2.14.1/src/python/pants/backend/python/lint/flake8/flake8.lock for the default lockfile contents.

Set to the string <none> to opt out of using a lockfile. We do not recommend this, though, as lockfiles are essential for reproducible builds and supply-chain security.

To use a custom lockfile, set this option to a file path relative to the build root, then run ./pants generate-lockfiles --resolve=flake8.

Alternatively, you can set this option to the path to a custom lockfile using pip's requirements.txt-style, ideally with --hash. Set [python].invalid_lockfile_behavior = 'ignore' so that Pants does not complain about missing lockfile headers.


console_script

--flake8-console-script=<str>

PANTS_FLAKE8_CONSOLE_SCRIPT

default: flake8

The console script for the tool. Using this option is generally preferable to (and mutually exclusive with) specifying an --entry-point since console script names have a higher expectation of staying stable across releases of the tool. Usually, you will not want to change this from the default.


entry_point

--flake8-entry-point=<str>

PANTS_FLAKE8_ENTRY_POINT

default: None

The entry point for the tool. Generally you only want to use this option if the tool does not offer a --console-script (which this option is mutually exclusive with). Usually, you will not want to change this from the default.


config

--flake8-config=<file_option>

PANTS_FLAKE8_CONFIG

default: None

Path to an INI config file understood by Flake8 (https://flake8.pycqa.org/en/latest/user/configuration.html).

Setting this option will disable [flake8].config_discovery. Use this option if the config is located in a non-standard location.


extra_files

--flake8-extra-files="[<file_option>, <file_option>, ...]"

PANTS_FLAKE8_EXTRA_FILES

default: []

Paths to extra files to include in the sandbox. This can be useful for Flake8 plugins,
like including config files for the flake8-bandit plugin.


config_discovery

--[no-]flake8-config-discovery

PANTS_FLAKE8_CONFIG_DISCOVERY

default: True

If true, Pants will include any relevant config files during runs (.flake8, flake8, setup.cfg, and tox.ini).

Use [flake8].config instead if your config is in a non-standard location.


source_plugins

--flake8-source-plugins="[<target_option>, <target_option>, ...]"

PANTS_FLAKE8_SOURCE_PLUGINS

default: []

An optional list of python_sources target addresses to load first-party plugins.

You must set the plugin's parent directory as a source root. For example, if your plugin is at build-support/flake8/custom_plugin.py, add 'build-support/flake8' to [source].root_patterns in pants.toml. This is necessary for Pants to know how to tell Flake8 to discover your plugin. See Source roots

You must also set [flake8:local-plugins] in your Flake8 config file.

For example:

```
[flake8:local-plugins]
    extension =
        CUSTOMCODE = custom_plugin:MyChecker
```

While your plugin's code can depend on other first-party code and third-party requirements, all first-party dependencies of the plugin must live in the same directory or a subdirectory.

To instead load third-party plugins, set the option [flake8].extra_requirements.

Tip: it's often helpful to define a dedicated 'resolve' via [python].resolves for your Flake8 plugins such as 'flake8-plugins' so that the third-party requirements used by your plugin, like flake8, do not mix with the rest of your project. Read that option's help message for more info on resolves.


Deprecated options

None