Python Manager Installation and Management Guide for Windows

⚠️ Important Notice (Python 3.16+): Starting from Python 3.16, the traditional .exe/.msi installer is deprecated and replaced by the Python Install Manager. Use py or pymanager commands for better multi-version management. Why? Provides automatic installation, unified version management, better conflict resolution, and seamless updates without manual PATH configuration.

📥 Download Python

Official Download: Python Downloads | Latest stable versions: 3.13.x, 3.12.x, 3.11.x

Installation Types: Use MSIX for better security (Windows 10/11) or MSI for legacy systems (Windows 7/8). MSIX auto-updates and runs in sandbox mode.

Documentation: Official Windows Setup Guide

🔍 Check Installed Python Versions

View all Python installations on your system with their paths:

py --list         # Shows installed versions
    pymanager list    # Alternative manager
    py --list-path    # Shows installation paths
    py -0p            # Get default Python path

Example Output: -V:3.13 * -V:3.12 -V:3.11

⚙️ Install Specific Python Version

Use pymanager to install multiple Python versions side-by-side:

pymanager install 3.12.8
    pymanager list    # Verify installation

🔄 Switch Python Versions

Temporary Change (Current Session Only):

set PY_PYTHON=3.13    # CMD
    $env:PY_PYTHON="3.13"  # PowerShell

Permanent Change (System-wide):

setx PY_PYTHON "3.13"  # Sets environment variable permanently

Run Script with Specific Version:

py -3.12 myfile.py           # Run script with Python 3.12
    py -3.13 -m venv myenv       # Create venv with Python 3.13
    py -3.11 -c "import sys; print(sys.version)"  # Quick version check

📦 Pip Package Management

Best Practice: Always use virtual environments to avoid dependency conflicts. For global installation:

py -3.10 -m pip install paramiko      # Install specific package
    py -3.10 -m pip install requests flask # Multiple packages

Install from requirements.txt:

py -3.10 -m pip install -r requirements.txt

Upgrade Pip to Latest Version:

py -3.10 -m pip install --upgrade pip

List All Installed Packages:

py -3.13 -m pip list           # All packages
    py -3.13 -m pip list --outdated # Outdated packages only
    py -3.13 -m pip show requests   # Details of specific package

🌳 View Package Dependencies (DevOps Essential)

Visualize package dependency tree to understand relationships and troubleshoot conflicts:

py -3.10 -m pip install pipdeptree  # Install tool
    py -3.10 -m pipdeptree               # Show all dependencies
    py -3.10 -m pipdeptree -p requests   # Dependencies of specific package
    py -3.10 -m pipdeptree --reverse     # Show reverse dependencies

💡 Virtual Environment Management

Create isolated Python environments for each project:

# Create virtual environment
    py -3.12 -m venv myproject_env

    # Activate environment
    myproject_env\Scripts\activate        # CMD
    myproject_env\Scripts\Activate.ps1    # PowerShell

    # Install packages in venv
    pip install django pandas numpy

    # Deactivate when done
    deactivate

🚀 Pro Tips

• Add Python to PATH: Check "Add Python to PATH" during installation for easy access
• py launcher: Use py instead of python for better version management on Windows
• Keep Updated: Regularly update pip with py -m pip install --upgrade pip
• Requirements: Generate requirements.txt with pip freeze > requirements.txt
• Cache Clear: Clear pip cache if installation fails: py -m pip cache purge

Related: Python Virtual Environments | PyPI Package Registry | pip Commands Cheat Sheet