Commands

$ rattle COMMAND [OPTIONS] ...

Use -h or --help on any command to print its supported options.

Shared lint/fix options

The following options are available on commands that check or fix code.

--config / -c CONFIG

Use a specific config file instead of discovered configuration.

--exclude / -e PATTERN

Replace configured exclude patterns. This option may be passed more than once. Like Ruff’s --exclude, direct path arguments are also excluded when they match the pattern.

$ rattle lint . --exclude "generated/**"

--extend-exclude PATTERN

Add exclude patterns. This option may be passed more than once. Direct path arguments are still checked unless they are excluded by configuration with force-exclude.

$ rattle lint . --extend-exclude "docs/_build/**"

--rules / -r RULES

Run only the given rules or rule collections.

This takes a comma-separated list of rule selectors, with the same accepted forms as enable and disable:

• import selectors such as rattle.rules.fixit_extra:use-f-string

• built-in rule collections such as blank-lines, fixit, or fixit-extra

• exact built-in rule names such as use-f-string

• exact local rule names such as my-custom-rule, when the local rule module is already configured for the target path

For example:

$ rattle lint --rules "use-f-string" path/to/file.py
$ rattle lint --rules "my-custom-rule" path/to/file.py
$ rattle lint --rules "fixit,fixit-extra" path/to/file.py

--jobs / -j JOBS

Number of worker processes to use when checking multiple files.

--compact

Print compact diagnostics.

--quiet / -q

Print only the final summary. --quiet cannot be used with --diff, --stats, or fix --interactive.

--diff / -d

Show fixes as unified diffs.

--stats

Print violation counts by rule.

lint

Check files for Rattle violations. Use - PATH to check code from standard input as PATH.

$ rattle lint [OPTIONS] [PATH ...]

fix

Apply available autofixes to files. Use - PATH to fix code from standard input as PATH and write the fixed code to standard output.

$ rattle fix [OPTIONS] [--interactive] [PATH ...]

--interactive / -i

Prompt before applying each autofix. Press y to apply, n to skip, or q to stop prompting and leave the remaining fixes unapplied. This option cannot be used with standard input.

lsp

Start the language server providing IDE features over LSP. This command is only available if Rattle is installed with the lsp extras, for example pip install "rattle-lint[lsp]". See IDE for more details.

$ rattle lsp [--no-stdio] [--tcp PORT | --ws PORT]

--config / -c CONFIG

Use a specific config file instead of discovered configuration.

--no-stdio

Disable the default stdio transport when serving over TCP or WebSocket.

--tcp PORT

Serve LSP over TCP on PORT.

--ws PORT

Serve LSP over WebSocket on PORT.

--debounce-interval SECONDS

Delay diagnostics after document changes, in seconds. Default: 0.5.

rules

Display the lint rules enabled for the current configuration. Pass paths to see the rules resolved for those files or directories.

$ rattle rules [OPTIONS] [PATH ...]

--config / -c CONFIG

Use a specific config file instead of discovered configuration.

--test

Test enabled lint rules using their VALID and INVALID test cases.

explain

Display detailed information about one lint rule.

$ rattle explain [OPTIONS] RULE

--config / -c CONFIG

Use a specific config file instead of discovered configuration.

--json

Print rule information as JSON.

validate

Validate Rattle configuration. When no path is provided, Rattle validates pyproject.toml from the current directory.

$ rattle validate
$ rattle validate pyproject.toml

Environment variables

RATTLE_DEBUG=1

Enable debug logging.

RATTLE_METRICS=1

Print internal run metrics for lint and fix.