Python Set up Guide

Setting Up Python 3.13, Virtual Environments, and Nexus Repository

📌 Introduction

This guide walks you through setting up Python 3.13, configuring pip, and working with virtual environments. Additionally, it includes steps for integrating with a custom package repository (such as Nexus or PyPI mirrors).

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🔹 Step 1: Uninstall Existing Python Versions (If Needed)

If you have older Python versions and want a fresh installation, uninstall them first:

1. Open Control Panel → Programs & Features → Uninstall Python.
2. Delete leftover Python folders manually:

   C:\Users\YourUsername\AppData\Local\Programs\Python\
   C:\PythonXX\  # (If installed in Program Files)

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🔹 Step 2: Download and Install Python 3.13

1. Visit the official Python website and download Python 3.13.
2. Run the installer and select Customize Installation.
3. Ensure the following options are checked: ✅ pip ✅ Add Python to PATH ✅ Install for all users (recommended)
4. Click Next and complete the installation.

Verify Installation

After installation, open Command Prompt and run:

python --version
pip --version

✅ Expected Output:

Python 3.13.x
pip 23.x.x from C:\Python313\Lib\site-packages\pip (python 3.13)

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🔹 Step 3: Configure pip with a Custom Package Repository (Optional)

If using a private package repository (e.g., Nexus, Artifactory, or a corporate mirror):

1. Set the package index URL:

   pip config set global.index-url https://your-custom-repo-url/

2. Set trusted hosts:

   pip config set global.trusted-host your-custom-repo-url

3. Set global timeout:

   pip config set global.timeout 60

To verify, try installing a package:

pip install pandas

✅ The package should download from your configured repository.

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🔹 Step 4: Setting Up a Virtual Environment

A virtual environment allows you to create an isolated Python workspace for your projects.

Create a Virtual Environment

Navigate to your project directory and run:

python -m venv myenv

✅ If successful, it will create a folder named myenv.

Activate the Virtual Environment

• Windows (Command Prompt):

  myenv\Scripts\activate

• Windows (PowerShell):

  myenv\Scripts\Activate.ps1

Your terminal will now show (myenv) at the beginning of the prompt.

Install Packages Inside Virtual Environment

pip install requests numpy pandas

Verify installed packages:

pip list

To deactivate the virtual environment:

deactivate

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🔹 Step 5: Running a Python Script

1. Create a new Python file outside the virtual environment:

   echo "print('Hello, World!')" > hello.py

2. Run the script:

   python hello.py

✅ Expected Output:

Hello, World!

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🔹 Step 6: Fixing ‘Script Not Found in PATH’ Warnings

If you see a warning like:

The script f2py.exe and numpy-config.exe are installed in 'C:\Users\YourUsername\AppData\Roaming\Python\Python313\Scripts\'
which is not on PATH. Consider adding this directory to PATH.

Solution: Add the Path to Environment Variables

1. Open System Environment Variables (sysdm.cpl → Advanced → Environment Variables).
2. Find Path under System Variables and click Edit.
3. Click New and add:

   C:\Users\YourUsername\AppData\Roaming\Python\Python313\Scripts\

4. Click OK, restart your terminal, and retry your commands.

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🚀 Conclusion

You have now successfully:
✔ Installed Python 3.13
✔ Configured pip with a package repository
✔ Created and activated a virtual environment
✔ Installed packages and ran a Python script

This setup ensures clean dependency management and avoids system-wide conflicts. Happy coding! 🎯

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