Taming Ruff: Enabling Rules Only on Specific Files
Ruff, a lightning-fast Python linter, is a powerful tool for ensuring code quality and consistency. But sometimes, you might want to apply specific rules only to certain files in your project. This could be due to legacy code, specific project requirements, or simply a preference for different coding styles.
Let's explore how to achieve this granular control over Ruff's rules.
Scenario: Imagine you have a project with a mix of Python files adhering to a stricter coding style, while older components maintain a looser format. You'd like to apply stricter rules to the newer files while keeping Ruff's helpful feedback on the legacy code.
Original Code (.ruff.toml):
[tool.ruff]
line-length = 120
# ... other rules
This configuration applies a maximum line length of 120 characters to all Python files in your project.
Solution: Ruff supports file-level configuration using .ruff.yaml files. This allows you to specify rule overrides for specific files or directories.
Modified Code:
# .ruff.yaml (for a specific directory)
[tool.ruff]
line-length = 120
# ... other rules
[tool.ruff.per-file-overrides]
"path/to/directory/**.py" = {
"line-length": 80,
}
This configuration now applies a line length limit of 80 characters only for Python files within the "path/to/directory" directory. This allows you to maintain the stricter 120 character limit for other parts of your project.
Key Insights:
- Granularity: File-level configuration provides maximum control over Ruff's behavior.
- Flexibility: You can override specific rules for different files or even individual lines of code.
- Clarity: Using separate
.ruff.yamlfiles helps keep your project organized and makes it easier to understand which rules apply where.
Example Use Cases:
- Legacy Code: Apply stricter rules to new code while maintaining a more relaxed approach for legacy components.
- Testing: Enable different rules in test files to accommodate specific testing needs.
- Configuration Files: Apply specific rules to configuration files to enforce consistent formatting.
Additional Value:
- This approach avoids having to manually disable rules throughout your codebase, saving time and reducing clutter.
- It promotes better code organization by clarifying which rules are active in different parts of the project.
Resources:
- Ruff Documentation: Find comprehensive information about Ruff, including details on per-file overrides.
- Ruff Configuration: Explore different ways to customize Ruff's behavior.
By leveraging file-level configuration with Ruff, you can tailor its behavior to your project's specific needs and maintain a healthy balance between consistency and flexibility.
