sphinx-linter 0.1.4

A lightweight Python linter for checking Sphinx docstrings.

sphinxlinter

A lightweight Python linter for Sphinx-style docstrings.
It validates structure, field consistency, and alignment between documentation and code.

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Overview

Sphinx-style docstrings are widely used across Python projects, but existing tools such as pydocstyle, pydoclint, and ruff focus primarily on general docstring formatting, PEP257 compliance, and style enforcement.

It is designed to complement, not overlap with, these tools.
It targets Sphinx-specific field list conventions and performs semantic consistency checks that go beyond what other linters cover.

Specifically, it focuses on:

• 🧩 Enforces Sphinx-style field list formatting
• 🛠️ Ensures consistency between docstrings, signatures, and implementation
• 📐 Validates section order, duplication, and syntax of documented types and errors
• 📊 Generates concise, CI-friendly reports
• ⚙️ Provides a minimalist CLI for easy workflow integration
• 🐍 Uses only the Python standard library for full compatibility
• 🧼 Promotes clean, maintainable documentation

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📦 Installation

Requires Python ≥ 3.9, but Python ≥ 3.11 is recommended to allow loading configuration files with tomlib from the standard library.

To install via pip, run:

pip install sphinx-linter

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⚡ Quick Start

CLI Tool

After installation via pip, you can run the sphinxlinter command directly from your terminal.

Run on the current directory:

• Run in the current directory: sphinxlinter .
• Or use the short alias: spxl .

Run on specific files or directories:

spxl path/to/file.py path/to/package/

[!NOTE]

Directories are scanned recursively for .py files, ignoring virtual environments and cache folders.

Standalone Script

Alternatively, you can download the standalone script by clicking the following link and run it with Python:

python sphinxlinter.py path/to/source/

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Command Line Usage

Argument / Option	Description
[FILES]	Files or directories to lint.
--help	Show help message and exit.
--enable	Enable specific rule codes (or ALL).
--disable	Disable specific rule codes (overrides --enable).
--ignore	Exclude directories (e.g. venv, .cache).
--statistics	Show per-rule violation counts.
--quiet	Print diagnostics, but nothing else
--version	Print version and exit
--config	If not provided, search upward from the [FILES]’ common ancestor for pyproject.toml
--isolated	Run in isolated mode, ignoring configuration files

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Setting Configuration

Configuration is done via pyproject.toml. The configuration section is [tool.sphinx-linter].

Configuration File Location

The linter uses --config to specify a configuration file. If this option is not provided, it searches for a configuration file starting at the common ancestor of all specified files/directories, moving upward until it finds one or reaches the filesystem root. If no configuration file is found, the linter runs with its default settings.

[!NOTE] Ignores search configuration files that meet any of the following conditions:

• Malformed pyproject.toml is detected.
• No [tool.sphinx-linter] section is found.
• Permissions prevent reading the file.

Also ignored if:

• The --isolated flag is set.
• A specific configuration file is provided via --config.
• Python version is below 3.11 (no tomllib support).

Example configuration:

[tool.sphinx-linter]
# Enable all rules, alternatively specify individual rule codes
enable = ["ALL"]
# Disable specific rules, taking precedence over enable
disable = ["DOC003", "DOC101"]
# Ignore specific directories from linting
ignore = ["venv", ".cache"]

[!NOTE]

Can also be set via CLI options --enable, --disable, and --ignore.

If both CLI options and configuration file are provided, CLI options take precedence.

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Output Format

When violations are found, the tool outputs lines in the following format:

path/to/file.py:LINE-NUMBER: [CODE] Description of the violation.

[!TIP]

Use --quiet to suppress output except for statistics summary if --statistics is also set.

[!NOTE]

• Exit code 0 means no violations were found; exit code 1 indicates that violations were detected.
• The tool never modifies source files.

Categories:

• DOC0xx: Structure and formatting issues
• DOC1xx: Parameter issues
• DOC2xx: Return issues
• DOC3xx: Raises issues
• DOC4xx: Variable issues

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Violation Codes

DOC0xx — Structure

Code	Description	Purpose	Enabled by Default
DOC001	Invalid docstring section	Detects unknown Sphinx fields.	Yes
DOC002	Malformed section	Ensures valid field list syntax.	Yes
DOC003	Missing blank line after docstring	Improves readability.	Yes
DOC004	Missing blank line between summary and sections	Enforces structure consistency.	Yes
DOC005	Too many consecutive blank lines	Prevents unnecessary whitespace.	Yes
DOC006	Trailing empty lines	Keeps docstrings compact.	Yes
DOC007	Misplaced section	Enforces section order and grouping.	Yes
DOC008	One-line docstring should end with a period	Complies with PEP 257.	Yes
DOC009	Docstring must not use more than 3 double quotes	Promotes consistent quoting.	Yes
DOC010	Section definition contains invalid whitespace	Ensures proper formatting.	Yes
DOC011	Trailing non-empty lines after last section	Maintains clean endings.	Yes
DOC012	Leading whitespaces in first non-blank line	Ensures no leading spaces before docstring content.	Yes

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[!NOTE]

DOC008: This rule differs from Ruff’s similar rule missing-trailing-period, which enforces a trailing period on the first line of both one-line and multi-line docstrings. By contrast, the rule DOC008 only enforces a trailing period on one-line docstrings, following the recommendation in PEP 257.

[!NOTE]

DOC009: Unlike Ruff triple-single-quotes, this rule only checks that multi-line docstrings do not start or end with more than three double quotes.

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DOC1xx — Parameters

Code	Description	Purpose	Enabled by Default
DOC101	Parameter documented but not in signature	Detects undocumented or extra parameters.	Yes
DOC102	Invalid parameter type syntax	Enforces valid Python type hints.	Yes
DOC103	Parameter type already in signature	Avoids redundant type info.	Yes
DOC104	Parameter type mismatch with annotation	Ensures consistency with annotations.	Yes
DOC105	Duplicated parameter	Prevents repetition.	Yes
DOC106	Parameter order mismatch with signature	Validates parameter order.	Yes
DOC107	Missing parameter in docstring	Ensures all parameters are documented	No

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DOC2xx — Returns

Code	Description	Purpose	Enabled by Default
DOC201	Return documented but function has no return statement	Detects unnecessary return sections.	Yes
DOC202	Invalid return type syntax	Enforces valid type expressions.	Yes
DOC203	Return type already in signature	Avoids redundancy.	Yes
DOC204	Return type mismatch with annotation	Validates against function annotations.	Yes
DOC205	Duplicated return section	Prevents duplication.	Yes

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DOC3xx — Raises

Code	Description	Purpose	Enabled by Default
DOC302	Invalid exception type syntax	Ensures valid Python exception syntax.	Yes
DOC305	Duplicated exception type	Prevents redundant entries.	Yes

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DOC4xx — Variables

Code	Description	Purpose	Enabled by Default
DOC402	Invalid variable type syntax	Enforces valid Python type hints.	Yes
DOC403	Variable name contains invalid whitespace	Ensures valid identifiers.	Yes
DOC405	Duplicated variable	Prevents repetition.	Yes

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How It Works

The tool statically analyzes Python source code using the built-in AST module:

1. Parses FunctionDef, AsyncFunctionDef, ClassDef, and Module nodes.
2. Extracts Sphinx-style docstring fields.
3. Validates structure, syntax, and consistency with annotations.

The tool prints findings to stdout and never modifies source files.

CI Integration:
Treat any output as a failure signal in your build pipeline.

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🛠️ Development

To contribute to the project, you can run the following commands for testing and documentation:

First, ensure you have the latest version of pip:

python -m pip install --upgrade pip

Running Tests

pip install --group=test --upgrade # Install test dependencies, skip if already installed
python -m pytest tests/ # Run all tests
python -m pytest tests/ --cov # Run tests with coverage

Running Linter

pip install --group=lint --upgrade  # Install lint dependencies, skip if already installed
ruff check . # Run linter

🗒️ License

This project is licensed under the MIT license._