ruff-score 0.3.0

A Pylint-style scoring system for Ruff linter output

Ruff Score 🎯

A Pylint-style scoring system for Ruff linter output. Get a numerical quality score (0-10) for your Python code based on Ruff's analysis, using a rule-category mapping that covers every prefix in Ruff's rule set.

Features

• 🎯 Pylint-style scoring: Familiar 0-10 quality score system, using Pylint's own formula
• 🔧 Ruff integration: Built on top of the fast Ruff linter
• 🗂️ Full rule coverage: Every Ruff prefix (E, F, PLE/PLC/PLR/PLW, ASYNC, S, TRY, RUF, and 40+ more) is mapped to a Pylint-style category and severity weight — not just a handful of common ones
• ⚖️ Two-level weighting: Issues are bucketed into error / warning / convention / refactor, and within a category, individual rules can carry different weights (e.g. a SQL-injection finding counts for more than a stray print)
• 📊 Detailed reports: Categorized issue breakdown with a printable summary
• 📁 File & directory support: Analyze single files or entire projects
• ⚙️ Configurable: Use your existing Ruff configuration file, and override weights/categories in Python

Installation

pip install ruff-score

Quick Start

from ruff_score import RuffScorer

scorer = RuffScorer()

# Score a single file
result = scorer.score_file("myfile.py")
print(f"Score: {result['score']:.2f}/10.00")

# Score a directory
result = scorer.score_directory("src/")
scorer.print_report(result)

# Score against a specific Ruff config
result = scorer.score_directory("src/", config_file="pyproject.toml")

How It Works

Ruff Score uses the same scoring formula as Pylint:

Score = 10.0 - ((5*errors + warnings + refactor + convention) / statements * 10)

statements is the number of AST statement nodes in the analyzed file(s), and errors / warnings / refactor / convention are the weighted issue totals for each category — not just raw counts. So a category's contribution to the score is the sum of each issue's individual rule weight, which means two "warning"-category issues aren't necessarily worth the same amount if one rule is riskier than another.

Rule Categories & Weights

Every Ruff prefix is mapped to one of four Pylint-style categories, based on Ruff's documented rule set:

Category	Meaning	Example prefixes	Typical weight
Error	Real bugs / correctness issues	E (pycodestyle), F (Pyflakes), PLE (Pylint errors), AIR (Airflow)	3–5
Warning	Security risks and likely-bug patterns	S (bandit/security), B (bugbear), ASYNC, TRY, PERF, T20/T10, DTZ, PLW	1–4
Convention	Naming, docs, style, imports	N (naming), D (docstrings), ANN, I (isort), Q, COM, PLC	1
Refactor	Modernization / simplification	UP (pyupgrade), SIM (simplify), PLR, PTH, C4, RUF	1

The full mapping (RULE_CATEGORIES and RULE_WEIGHTS) lives at the top of ruff_scorer.py and covers ~50 rule prefixes, including ones that embed a digit in the prefix itself (e.g. C4, C90, T10, T20) and multi-letter prefixes (e.g. PLE, ASYNC, TRY). Any prefix Ruff adds in the future that isn't in the table falls back to default_weight / default_category.

Score Interpretation

• 9.0-10.0: Excellent code quality
• 7.0-8.9: Good code quality
• 5.0-6.9: Needs improvement
• 0.0-4.9: Poor code quality

Example Output

==================================================
RUFF QUALITY SCORE REPORT
==================================================
Target: src/
Score: 8.45/10.00
Statements analyzed: 1,247
Files analyzed: 23
Total issues: 12

Issues by category:
  Error: 0
  Warning: 3
  Convention: 8
  Refactor: 1

Good code quality

Advanced Usage

Custom Weights and Categories

from ruff_scorer import RuffScorer

# Change the fallback used for any rule prefix not in RULE_WEIGHTS/RULE_CATEGORIES
scorer = RuffScorer(default_weight=2, default_category="warning")

# Override the weight or category for a specific prefix
scorer.RULE_WEIGHTS["D"] = 1        # docstring issues
scorer.RULE_CATEGORIES["D"] = "convention"

# Inspect how a given rule code resolves
scorer.get_rule_weight("S608")      # -> 4
scorer.get_rule_category("S608")    # -> "warning"

Integration with CI/CD

# check_quality.py
import sys
from ruff_scorer import RuffScorer

scorer = RuffScorer()
result = scorer.score_directory("src/")
scorer.print_report(result)

THRESHOLD = 7.0
sys.exit(0 if result["score"] >= THRESHOLD else 1)

python check_quality.py && echo "Quality check passed!" || echo "Quality check failed!"

Configuration

Ruff Score respects your existing Ruff configuration by passing it straight through to ruff check --config. Place your settings in:

• pyproject.toml
• ruff.toml
• .ruff.toml

Example configuration:

[tool.ruff]
line-length = 88
target-version = "py38"

[tool.ruff.lint]
select = ["E", "F", "W", "C", "N", "D", "S", "B"]
ignore = ["E501", "D100"]

Requirements

• Python 3.8+
• Ruff installed and available on your PATH

License

MIT License - see LICENSE file for details.

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

Related Projects

• Ruff - The fast Python linter
• Pylint - The original Python code quality tool