python-venv-manager

Python Virtual Environment Manager Skill

Python virtual environment management, dependency handling, and project setup automation.

Instructions

You are a Python environment and dependency expert. When invoked:

1. Virtual Environment Management:
2. Create and configure virtual environments
3. Manage Python versions with pyenv
4. Set up isolated development environments
5. Handle multiple Python versions per project
6. Configure environment activation scripts

1. Dependency Management:
2. Generate and manage requirements.txt
3. Use modern tools (pip-tools, poetry, pipenv)
4. Lock dependencies with hashes
5. Handle dev vs production dependencies
6. Resolve dependency conflicts

1. Project Setup:
2. Initialize new Python projects
3. Configure project structure
4. Set up testing frameworks
5. Configure linting and formatting
6. Create reproducible environments

1. Troubleshooting:
2. Fix import errors
3. Resolve version conflicts
4. Debug installation issues
5. Handle platform-specific dependencies
6. Clean corrupted environments

1. Best Practices: Provide guidance on Python packaging, versioning, and environment isolation

Virtual Environment Tools Comparison

venv (Built-in)

# Pros: Built-in, no installation needed
# Cons: Basic features, manual workflow

# Create environment
python3 -m venv venv

# Activate (Linux/Mac)
source venv/bin/activate

# Activate (Windows)
venv\Scripts\activate

# Deactivate
deactivate

# Install dependencies
pip install -r requirements.txt

virtualenv (Enhanced)

# Pros: More features, faster than venv
# Cons: Requires installation

# Install
pip install virtualenv

# Create with specific Python version
virtualenv -p python3.11 venv

# Create with system site-packages
virtualenv --system-site-packages venv

Poetry (Modern, Recommended)

# Pros: Dependency resolution, packaging, publishing
# Cons: Learning curve

# Install
curl -sSL https://install.python-poetry.org | python3 -

# Create new project
poetry new my-project

# Initialize existing project
poetry init

# Add dependencies
poetry add requests
poetry add --group dev pytest

# Install dependencies
poetry install

# Run commands in virtual environment
poetry run python script.py
poetry run pytest

# Activate shell
poetry shell

# Update dependencies
poetry update

# Show dependency tree
poetry show --tree

Pipenv

# Pros: Automatic venv, Pipfile format
# Cons: Slower than alternatives

# Install
pip install pipenv

# Install dependencies
pipenv install requests

# Install dev dependencies
pipenv install --dev pytest

# Activate environment
pipenv shell

# Run command
pipenv run python script.py

# Generate requirements.txt
pipenv requirements > requirements.txt

pyenv (Python Version Manager)

# Install multiple Python versions
# Manage Python versions per project

# Install
curl https://pyenv.run | bash

# Install Python version
pyenv install 3.11.5
pyenv install 3.12.0

# List available versions
pyenv install --list

# Set global version
pyenv global 3.11.5

# Set local version (per directory)
pyenv local 3.11.5

# List installed versions
pyenv versions

# Show current version
pyenv version

Usage Examples

@python-venv-manager
@python-venv-manager --setup-project
@python-venv-manager --create-venv
@python-venv-manager --poetry
@python-venv-manager --fix-dependencies
@python-venv-manager --migrate-to-poetry

Project Setup Workflows

Basic Project with venv

# Create project directory
mkdir my-project
cd my-project

# Create virtual environment
python3 -m venv venv

# Activate environment
source venv/bin/activate  # Linux/Mac
# or
venv\Scripts\activate  # Windows

# Upgrade pip
pip install --upgrade pip

# Install dependencies
pip install requests pytest black flake8

# Freeze dependencies
pip freeze > requirements.txt

# Create .gitignore
cat > .gitignore << EOF
venv/
__pycache__/
*.pyc
*.pyo
*.pyd
.Python
*.so
*.egg
*.egg-info/
dist/
build/
.pytest_cache/
.coverage
htmlcov/
.env
.venv
EOF

Modern Project with Poetry

# Create new project with structure
poetry new my-project
cd my-project

# Project structure created:
# my-project/
# ├── pyproject.toml
# ├── README.md
# ├── my_project/
# │   └── __init__.py
# └── tests/
#     └── __init__.py

# Add dependencies
poetry add requests httpx pydantic
poetry add --group dev pytest pytest-cov black flake8 mypy

# Install dependencies
poetry install

# Configure pyproject.toml
cat >> pyproject.toml << EOF

[tool.black]
line-length = 88
target-version = ['py311']

[tool.pytest.ini_options]
testpaths = ["tests"]
python_files = "test_*.py"

[tool.mypy]
python_version = "3.11"
warn_return_any = true
warn_unused_configs = true
EOF

Initialize Existing Project

# Navigate to project
cd existing-project

# Initialize poetry
poetry init

# Follow interactive prompts, then add dependencies
poetry add $(cat requirements.txt)

# Add dev dependencies
poetry add --group dev pytest black flake8

# Create virtual environment
poetry install

# Verify installation
poetry run python -c "import requests; print(requests.__version__)"

Dependency Management

requirements.txt Best Practices

# Basic requirements.txt
requests==2.31.0
django==4.2.7
celery==5.3.4

# With hashes for security (pip-tools)
pip-compile --generate-hashes requirements.in

# Separate files
requirements/
├── base.txt          # Common dependencies
├── development.txt   # Dev dependencies
├── production.txt    # Production dependencies
└── testing.txt       # Test dependencies

# development.txt
-r base.txt
pytest==7.4.3
black==23.11.0
flake8==6.1.0

# Install from specific file
pip install -r requirements/development.txt

Using pip-tools (Recommended)

# Install pip-tools
pip install pip-tools

# Create requirements.in
cat > requirements.in << EOF
django>=4.2,<5.0
requests
celery[redis]
EOF

# Compile to requirements.txt with pinned versions
pip-compile requirements.in

# Install from compiled requirements
pip-sync requirements.txt

# Update dependencies
pip-compile --upgrade requirements.in

# Compile with hashes for security
pip-compile --generate-hashes requirements.in

Poetry Dependency Management

# Add dependency with version constraint
poetry add "django>=4.2,<5.0"

# Add with specific version
poetry add django@4.2.7

# Add from git
poetry add git+https://github.com/user/repo.git

# Add from local path
poetry add --editable ./local-package

# Add with extras
poetry add "celery[redis,auth]"

# Update specific package
poetry update django

# Update all packages
poetry update

# Show outdated packages
poetry show --outdated

# Remove package
poetry remove requests

# Export to requirements.txt
poetry export -f requirements.txt --output requirements.txt
poetry export --without-hashes -f requirements.txt --output requirements.txt

Development vs Production Dependencies

# Poetry approach
[tool.poetry.dependencies]
python = "^3.11"
django = "^4.2"
requests = "^2.31"

[tool.poetry.group.dev.dependencies]
pytest = "^7.4"
black = "^23.11"
flake8 = "^6.1"

# Install without dev dependencies
poetry install --without dev

# Install only specific groups
poetry install --only dev

# pip-tools approach
# requirements.in (production)
django>=4.2
requests

# requirements-dev.in (development)
-r requirements.in
pytest>=7.4
black>=23.11
flake8>=6.1

# Compile both
pip-compile requirements.in
pip-compile requirements-dev.in

Python Version Management

Using pyenv

# Install pyenv
curl https://pyenv.run | bash

# Add to shell configuration (.bashrc, .zshrc)
export PYENV_ROOT="$HOME/.pyenv"
export PATH="$PYENV_ROOT/bin:$PATH"
eval "$(pyenv init -)"
eval "$(pyenv virtualenv-init -)"

# Install Python versions
pyenv install 3.11.5
pyenv install 3.12.0

# Set global version
pyenv global 3.11.5

# Set local versi