creosote 2.3.7

Identify unused dependencies and avoid a bloated virtual environment.

creosote

Identify unused dependencies and avoid a bloated virtual environment.

:zap: Quickstart

Install creosote in separate virtual environment (using e.g. pipx):

pipx install creosote

Scan virtual environment for unused packages (PEP-621 example below, but Poetry, Pipenv and requirements.txt files are also supported, see this table):

$ creosote
Found packages in pyproject.toml: distlib, dotty-dict, loguru, pip-requirements-parser, requests, toml
Oh no, bloated venv! 🤢 🪣
Unused packages found: requests

And after having removed/uninstalled requests:

$ creosote
Found packages in pyproject.toml: distlib, dotty-dict, loguru, pip-requirements-parser, toml
No unused packages found! ✨

Get help:

creosote --help

🤔 How this works

Some data is required as input:

Argument	Default value	Description
--venv	.venv	The path to your virtual environment.
--paths	src	The path to your source code, one or more files/folders.
--deps-file	pyproject.toml	The path to the file specifying your dependencies, like pyproject.toml, requirements_*.txt | .in.
--sections	project.dependencies	One or more toml sections to parse, e.g. project.dependencies.

The creosote tool will first scan the given python file(s) for all its imports. Then it fetches all package names (from the dependencies spec file). Finally, all imports are associated with their corresponding package name (requires the virtual environment for resolving). If a package does not have any imports associated, it will be considered to be unused.

:triumph: Known limitations

• importlib imports are not detected by the AST parser (a great first contribution for anyone inclined 😄, reach out or start here).

🥧 History and ambition

The idea of a package like this was born from having gotten security vulnerability reports about production dependencies (shipped into production) which turned out to not not even be in use.

The goal would be to be able to run this tool in CI, which will catch cases where the developer forgets to remove unused dependencies. An example of such a case could be when doing refactorings.

Note: The creosote tool supports identifying both unused production dependencies and developer dependencies. It all depends on what you would like to achieve.

:raised_eyebrow: FAQ

Which dependency specification tooling/standards are supported?

Tool/standard	Supported	--deps-file value	Example --sections values
PEP-621 ⭐	:white_check_mark:	pyproject.toml	project.dependencies, project.optional-dependencies.<GROUP>
Poetry	:white_check_mark:	pyproject.toml	tool.poetry.dependencies, tool.poetry.dev-dependencies (legacy), tool.poetry.group.<GROUP>.dependencies
Pipenv	:white_check_mark:	pyproject.toml	packages, dev-packages
PEP-508 (requirements.txt, pip-tools)	:white_check_mark:	*.[txt|in]	N/A
Legacy Setuptools (setup.py)	❌

📔 Notes on PEP-508 (requirements.txt)

When using requirements.txt files to specify dependencies, there is no way to tell which part of requirements.txt specifies production vs developer dependencies. Therefore, you have to break your requirements.txt file into e.g. requirements-prod.txt and requirements-dev.txt and use any of them as input. When using pip-tools, you likely want to point Creosote to scan your *.in file(s).

Can I specify multiple toml sections?

Yes, you can specify a list of sections after the --sections argument. It all depends on what your setup looks like and what you set out to achieve.

Can I run Creosote in a GitHub Action workflow?

Yes, please see the action job example in .github/workflows/test.yml.

Can I run Creosote with pre-commit?

Yes, see example in .pre-commit-config.yaml.

Here's another example setup, if already have Creosote installed onto $PATH (via e.g. pipx).

# .pre-commit-config.yaml

repos:
  - repo: local
    hooks:
      - id: system
        name: creosote
        entry: creosote --venv .venv --paths src --deps-file pyproject.toml --sections project.dependencies
        pass_filenames: false
        files: \.(py|toml|txt|in|lock)$
        language: system

What's with the name "creosote"?

This tool has borrowed its name from the Monty Python scene about Mr. Creosote.

:woman_scientist: Development/debugging info

Install in-development builds

You can run in-development versions of Creosote. Examples below:

# Creosote build from main branch
$ pipx install --suffix=@main --force git+https://github.com/fredrikaverpil/creosote.git@main
$ creosote@main --venv .venv ...
$ pipx uninstall creosote@main

# Creosote build from PR #123
$ pipx install --suffix=@123 --force git+https://github.com/fredrikaverpil/creosote.git@refs/pull/123/head
$ creosote@123 --venv .venv ...
$ pipx uninstall creosote@123

Releasing

1. Bump version in src/creosote/__about__.py and .pre-commit-config.yaml.
2. GitHub Action will run automatically on creating a release and deploy the release onto PyPi.