pyproject-lens

Run one command. Get the useful stuff first.

pyproject-lens is a small, free health scanner for Python projects. Give it a folder and it looks for the easy-to-miss things that slowly turn into annoying bugs: a dependency you forgot to declare, a Python version claim that is too old, an .env file that is not ignored, a project with no tests, or a package that is hard to install.

It is made for that first ten seconds when you open a project and think: is this thing okay, or is it hiding problems?

pip install pyproject-lens
pyproject-lens .

No account. No config maze. Normal scans never change files or upload code anywhere. The optional --fix command is the one exception, and it only applies the safe fixes listed below.

What you get

The normal report is short and practical:

DEPENDENCIES  90/100
  WARNING: 'requests' is imported but not declared.
    Try: Add it to project.dependencies if it is a runtime dependency.

PROJECT HEALTH: 82/100  |  3 warning(s)

When it can, it points to the file and line too:

WARNING (src/app.py:12): 'requests' is imported but not declared.

The score is not a grade. It is a quick, predictable summary: every section starts at 100, the scanner deducts points only for checks it found, and the final health score is the average.

Install

pip install pyproject-lens

Python 3.9 or newer is supported.

Use it

Scan the current project:

pyproject-lens .

Run it as a module (works even when the console script is not on PATH):

python -m pyproject_lens .

Check the version:

pyproject-lens --version

Scan another folder:

pyproject-lens ./my-project

Save reports for CI, a code review, or later:

pyproject-lens . --json report.json
pyproject-lens . --markdown report.md
pyproject-lens . --html report.html

The HTML report is one standalone file. Open it in a browser or attach it to a project review.

CI mode

Fail a job when the score is too low:

pyproject-lens . --ci --minimum-score 75

Or keep the threshold in pyproject.toml:

[tool.pyproject-lens]
minimum_score = 75

Then use:

pyproject-lens . --ci

Safe fixes

Use --fix when you want the tool to make a small, deterministic fix:

pyproject-lens . --fix

Current fixes:

• Missing [project] fields — adds project.name (from the folder name), project.version (0.1.0), and project.requires-python (>=3.9) when they are absent, and adds project.readme only if a README file actually exists. Fields listed in dynamic are never touched.
• .env not ignored — adds .env to .gitignore when a .env file is present but not ignored.
• No .gitignore — creates a starter .gitignore (caches, virtualenvs, build output) for Git repositories that have none.

The guarantees:

• Never overwrites. Existing values, keys, and comments stay byte-for-byte identical; the fix only fills gaps.
• Idempotent. Running --fix twice changes nothing the second time.
• Never guesses blindly. If pyproject.toml cannot be parsed, it is left untouched.
• Never edits Python source code, dependencies, or versions managed by dynamic tooling.

You can call the same fixes from Python:

from pyproject_lens import apply_safe_fixes

apply_safe_fixes("./my-project")

Safety limits (no hangs, ever)

The scanner never walks a directory tree without bounds. It skips virtual environments, caches, build output, node_modules, and other non-project directories, never follows symlinked directories, and stops with a clear error instead of hanging when a tree is unusually large:

• max 5,000 Python files per scan
• max 12 directory levels deep

If a legitimate project hits a cap, raise it:

pyproject-lens . --max-files 20000 --max-depth 20

You can also skip parts of the tree:

pyproject-lens . --exclude "vendor/*" --exclude "scripts/*"

The exit code is 2 and the message starts with SCAN ABORTED: when a cap is hit, so CI jobs fail fast instead of timing out.

Or keep the limits in pyproject.toml (explicit flags win over the config):

[tool.pyproject-lens]
max_files = 20000
max_depth = 20
exclude = ["vendor/*", "examples/*"]

What it checks

• Packaging — pyproject.toml, project name, supported Python version, and README basics.
• Dependencies — imports compared with project.dependencies, including common aliases such as yaml / PyYAML, PIL / Pillow, and sklearn / scikit-learn. Imports only listed in requirements*.txt get a gentle info note instead of a full warning. Local packages are never flagged.
• Python compatibility — syntax gated on the declared floor: match/case (3.10) and type aliases (3.12) are checked against a properly parsed lower bound from requires-python, not a naive regex.
• Project structure — src/ layouts, packages, and root crowding that understands entry-point scripts (app.py, manage.py, cli.py...) and tooling files, so single-file Flask/Django apps are not scolded.
• Testing — test files, test tooling config ([tool.pytest], tox.ini, noxfile.py), and a test-to-source ratio that is reported as info, never claimed as coverage.
• Security basics — possible hard-coded secrets, eval, exec, shell=True, and .env files not clearly ignored.
• Documentation — README, install and usage hints, license, and contribution guide.
• Git hygiene — .gitignore and uncommitted changes when the folder is a Git repository.

This tool does not replace Ruff, pytest, Bandit, a dependency vulnerability scanner, or a human review. It is the friendly first pass before those tools.

Configuration reference

Everything lives under [tool.pyproject-lens] in your pyproject.toml:

Command-line flags override the config file.

Python API

Use the same scanner from your own script:

from pyproject_lens import analyze

report = analyze("./my-project")
print(report.score)
print(report.to_json())
report.to_html("report.html")

The API is read-only and raises pyproject_lens.analyzers.ScanningLimitExceeded if the tree is too large, so interactive tools can fail fast. The one exception is apply_safe_fixes(), which writes files exactly like --fix does.

Integrations

GitHub Actions

name: project-health
on: [push, pull_request]
jobs:
  lens:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-python@v5
        with:
          python-version: "3.12"
      - run: pip install pyproject-lens
      - run: pyproject-lens . --ci --minimum-score 70

Pre-commit hook

Save this as .git/hooks/pre-commit (and chmod +x it):

#!/bin/sh
pyproject-lens . --ci --minimum-score 60 || echo "pyproject-lens: health below threshold"

(Or wire the same command into your pre-commit framework config.)

VS Code / PyCharm

Run it as an external tool and jump to findings, since every warning carries file:line locations:

pyproject-lens $ProjectFileDirectory$ --json -

Why it is free

This project is MIT licensed and open source. All current features are free. The goal is to make a tool developers can run on any project without signing up for anything.

Development

python -m pip install -e .
python -m unittest discover -s tests
python -m build

Contributions are welcome. Keep checks useful, keep messages honest, and add a small test when fixing a bug.

Author

Samarth Chugh — GitHub: @Sam3360