reqdiff

Detect unused and undeclared Python dependencies.

reqdiff scans your Python project and reports:

Unused dependencies — packages listed in your requirements that are never imported
Undeclared imports — packages imported in your code that are missing from requirements

Installation

pip install reqdiff

Usage

# Scan the current directory
reqdiff .

# Scan a specific project
reqdiff /path/to/project

# Point to a specific requirements file
reqdiff . --requirements requirements/prod.txt

# Include dev dependencies
reqdiff . --include-dev

# Suppress specific packages from the unused report
reqdiff . --ignore-package boto3

# Output as JSON (useful for CI tooling)
reqdiff . --json

Example output

Scanning: /my/project/**/*.py
Scanned 12 file(s) using 1 requirements source(s)

Unused dependencies (listed in requirements but never imported):
  • boto3

Undeclared imports (imported in code but not in requirements):
  • httpx

✗ Found 2 issues

Exit codes: 0 = clean, 1 = issues found, 2 = scan error.

Supported requirements formats

Format	Support
`requirements.txt`	✓ Full (including `-r` includes)
`pyproject.toml`	✓ PEP 621 `[project.dependencies]` + Poetry
`setup.cfg`	✓ `[options] install_requires`

Configuration

Add a [tool.reqdiff] section to your pyproject.toml:

[tool.reqdiff]
exclude_dirs = [".venv", "venv", "docs"]
ignore_packages = ["boto3"]        # treat as always-used
ignore_imports = ["mypy_extensions"]  # ignore in undeclared report
include_dev = false

Use as a library

from reqdiff import run_check

result = run_check(".")
print(result.unused_deps)       # ["boto3"]
print(result.undeclared_imports)  # ["httpx"]
print(result.has_issues)          # True

Known limitations

Dynamic imports (importlib.import_module("name")) are not detected — only static import statements are analyzed.
setup.py (legacy format) is not supported; use pyproject.toml or setup.cfg instead.
Packages not installed in the current environment are resolved using a static mapping table. If a package is missing from the table, reqdiff falls back to treating the import name as the package name.

Contributing

Contributions welcome! Please open an issue or pull request on GitHub.

License

MIT

reqcheck