Python Dependency Management Rule

> !CAUTION] BEFORE any pip install: You MUST first detect the project's > existing dependency manager and use it correctly. Do NOT override the > project's established tooling.

Dependency Manager Detection

Before installing ANY Python package, check the workspace for these files in priority order:

1. Signal: uv.lock or pyproject.toml with [tool.uv]

• Tool: uv
• Install: uv add <package>
• Setup: uv sync

1. Signal: pyproject.toml with [tool.poetry]

• Tool: Poetry
• Install: poetry add <package>
• Setup: poetry install

1. Signal: Pipfile

• Tool: Pipenv
• Install: pipenv install <package>
• Setup: pipenv install

1. Signal: environment.yml

• Tool: Conda
• Install: conda install <package>
• Setup: conda env create -f environment.yml

1. Signal: requirements.txt only

• Tool: venv + pip
• Install: .venv/bin/pip install <package>
• Setup: .venv/bin/pip install -r requirements.txt

1. Signal: None of the above

• Tool: venv + pip (default)
• Install: .venv/bin/pip install <package>
• Setup: .venv/bin/pip install -r requirements.txt

Default: venv + pip

If no dependency manager is detected, use venv + pip + requirements.txt as the default:

bash
# Initialize environment
python3 -m venv .venv

# Add dependencies
.venv/bin/pip install <package>

# Preserve state
.venv/bin/pip freeze > requirements.txt

Rules for venv + pip workflow:

• Always use .venv/bin/pip or .venv/bin/python (explicit path).
• After installing, run: .venv/bin/pip freeze > requirements.txt.
• When setting up: .venv/bin/pip install -r requirements.txt.

Prohibited

• NEVER run pip install globally
• NEVER override an existing dependency manager with a different one