Ruff vs. Pylint: A Comparison

Ruff does not completely cover all of Pylint’s functionality. While Ruff is exceptionally fast and supports a wide range of linting rules, it lacks some of the deeper, analysis-based checks that Pylint performs. Here’s a comparison of key areas where their functionality overlaps and differs:

1. Supported Rules and Coverage

• Ruff: Focuses on speed and provides broad coverage for stylistic, formatting, and common error checks (e.g., variable naming, unused imports, unused variables, type annotations, and simple logical checks).

• Pylint: Offers more extensive checks, including object-oriented checks (e.g., method signatures, class inheritance issues), control flow analysis, and specific code smells (e.g., too many arguments, cyclomatic complexity, and duplicate code). Pylint is also known for its configurable thresholds for complexity metrics and custom rules.

2. Error Types and Depth of Analysis

• Ruff: Targets primarily stylistic and performance issues, along with common errors that can be statically analyzed quickly. It doesn’t perform complex flow analysis, which can identify issues like potential bugs from misused variable scopes.

• Pylint: Performs in-depth checks, including flow analysis, class and method structure validations, and advanced bug detection (e.g., unhandled exceptions and unreachable code).

3. Configuration and Extensibility

• Ruff: Relatively lightweight configuration, generally configured through a pyproject.toml file or similar. Its primary focus is on quick, standard linting with minimal setup.

• Pylint: Highly configurable, allowing users to enable or disable specific checks, set strictness levels, and define custom thresholds. Pylint also supports plugins, enabling custom rule sets to be added, which can be essential for enforcing project-specific standards.

4. Performance

• Ruff: Designed for speed, making it much faster than Pylint, especially on larger codebases.

• Pylint: Known for being slower, as it performs more comprehensive checks and deeper analysis.

5. Summary of Overlap and Differences

Feature	Ruff	Pylint
Style Checks	✔️	✔️
Error Detection	✔️	✔️
Complexity Checks	❌	✔️
Flow Analysis	❌	✔️
OOP-Specific Checks	❌	✔️
Speed	⚡ Fast	⏳ Slower
Configurability	Basic	Extensive
Custom Plugins	Limited	Extensive

When to Use Ruff, Pylint, or Both

• Ruff: Best for fast feedback, stylistic checks, and general error detection in CI/CD pipelines where speed is essential.

• Pylint: More suitable for thorough code quality analysis, complex projects, or when deeper insight into code structure and design is required.

• Both: Many teams use Ruff for quick feedback and Pylint as a secondary step for in-depth analysis, especially in pre-commit hooks or CI pipelines.

In conclusion, while Ruff covers many basic checks similar to Pylint, it does not replace Pylint entirely in terms of depth and customization.