02: Python Environment Management

Concepts covered:

  • Advanced Python environment operations
  • Python environment initialization and configuration
  • Environment diagnostics and troubleshooting
  • Hatch MCP server wrapper management

Skills you will practice:

  • Initializing Python environments in existing Hatch environments
  • Viewing detailed Python environment information
  • Managing the hatch_mcp_server wrapper
  • Launching Python shells within environments

This article covers advanced Python environment management within Hatch environments.

Step 1: Initialize Python Environment

Add a Python environment to an existing Hatch environment:

# Initialize in current environment
hatch env python init --python-version 3.11

# Initialize in specific environment
hatch env python init --hatch_env my_env --python-version 3.12 --force

Python Initialization Options

  • --hatch_env - Target Hatch environment (defaults to current)
  • --python-version - Python version (e.g., 3.11, 3.12)
  • --force - Force recreation if Python environment exists
  • --no-hatch-mcp-server - Skip hatch_mcp_server wrapper installation
  • --hatch_mcp_server_tag - Git tag/branch for wrapper (e.g., ‘dev’, ‘v0.1.0’)

Step 2: View Python Environment Information

Get detailed information about a Python environment:

# Basic info for current environment
hatch env python info

# Detailed info for specific environment
hatch env python info --hatch_env my_env --detailed

Example output:

Python environment info for 'my_env':
  Status: Active
  Python executable: /path/to/conda/envs/my_env/bin/python
  Python version: 3.11.9
  Conda environment: my_env
  Environment path: /path/to/conda/envs/my_env
  Created: 2025-08-24T10:30:00
  Package count: 25
  Packages:
    - fastmcp (1.0.0)
    - mcp (1.0.0)
    - hatch-mcp-server (0.1.0)

Diagnostics:
  conda_available: true
  mamba_available: true
  environment_exists: true
  python_executable_valid: true

Step 3: Manage Hatch MCP Server Wrapper

The hatch_mcp_server wrapper provides integration between Hatch packages and MCP servers.

Add the wrapper to an environment:

hatch env python add-hatch-mcp --hatch_env my_env --tag v0.1.0

The wrapper is typically installed automatically when creating Python environments, but you can add it manually or update to specific versions.

Step 4: Launch Python Shell

Access the Python environment directly:

# Interactive shell
hatch env python shell --hatch_env my_env

# Run specific command
hatch env python shell --hatch_env my_env --cmd "import sys; print(sys.version)"

Step 5: Remove Python Environment

Remove only the Python environment while keeping the Hatch environment:

# With confirmation prompt
hatch env python remove --hatch_env my_env

# Force removal without prompt  
hatch env python remove --hatch_env my_env --force

This allows you to remove Python dependencies without affecting Hatch package installations.

Step 6: Troubleshooting Python Environments

Use the --detailed flag to diagnose issues:

hatch env python info --detailed

Common diagnostic information includes:

  • conda_available - Whether conda is installed and accessible
  • manager_executable - The path to conda/mamba executable that will be used
  • environment_path - The path to the conda environment
  • python_executable - The path to the Python executable used to run the MCP servers in the Hatch! packages.

Exercise:

  • Create a Hatch environment without Python, then add Python support afterwards. View the detailed information before and after Python initialization.
  • Remove the Python environment and verify it’s cleanly removed while keeping the Hatch environment intact.
  • Remove the Hatch environment and verify it’s cleanly removed.
Solution ```bash # Create environment without Python hatch env create test_python --no-python --description "Test Python addition" # Check info (should show no Python) hatch env python info --hatch_env test_python --detailed # Add Python environment hatch env python init --hatch_env test_python --python-version 3.11 # Check info again (should show Python details) hatch env python info --hatch_env test_python --detailed # Remove Python environment hatch env python remove --hatch_env test_python --force # Check info (should show no Python again) hatch env python info --hatch_env test_python --detailed # Remove Hatch environment hatch env remove test_python # Verify removal hatch env list ```

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