NOTE: The official GitHub Codespaces documentation provides detailed instructions to get started. A sample GitHub Codespace is available here: https://github.com/voirinprof/geolabspace

Introduction to GitHub Codespaces

GitHub Codespaces is a cloud-based development environment integrated with GitHub. It allows you to code directly in a browser or via VS Code without setting up a local environment. Preinstalled with Python, Git, and other tools, it’s ideal for quickly starting programming projects.

This guide shows you how to create a Codespace, write a simple Python program, and manage your code with Git.

Creating a Codespace

  1. Access a repository: Log in to GitHub and create or open a repository (for example, an empty project or a fork of an existing one).
  2. Launch a Codespace: Click on Code > Codespaces > Create codespace on main branch. GitHub will set up an Ubuntu environment with Python in seconds.
  3. Open the editor: The Codespace opens in your browser or in VS Code (if connected). You get access to a terminal and a code editor.

Open Codespaces

Tip: If you’re creating a new repository, add a README file to initialize the main branch.

Writing a Simple Python Program

Inside your Codespace, create a file named somme.py to calculate the sum of a list of numbers.

Example code:

def calculer_somme(nombres):
    """Calculates the sum of a list of numbers."""
    return sum(nombres)

# Example usage
liste = [1, 2, 3, 4, 5]
resultat = calculer_somme(liste)
print(f"The sum of {liste} is {resultat}")

To run the program:

  1. Open the terminal in the Codespace (shortcut: Ctrl + ~).
  2. Run the command:
python somme.py

Expected output:

The sum of [1, 2, 3, 4, 5] is 15

Tip: Use the Python extension in VS Code (preinstalled in Codespaces) for autocomplete and debugging.

Installing Libraries

If your project needs Python libraries, use pip. For example, to install numpy:

pip install numpy

Example using numpy to compute a sum:

import numpy as np

nombres = np.array([1, 2, 3, 4, 5])
somme = np.sum(nombres)
print(f"The sum with numpy is {somme}")

Run with:

python your_file.py

Managing Code with Git

Codespaces is integrated with Git, making version control easy.

  1. Check changes: 
    git status
  2. Add files: 
    git add somme.py
  3. Commit changes: 
    git commit -m "Add sum calculation script"
  4. Push to GitHub: 
    git push origin main

Your changes are now saved in the GitHub repository.

Tip: Commit frequently to avoid losing work, especially if the Codespace is stopped.

Best Practices

  • Organize your files: Keep a clear structure (e.g., a scripts/ folder for Python files).
  • Test your code: Add basic test cases to check results (e.g., test the function with [] or [-1, 1]).
  • Document your code: Use docstrings and comments to explain your code.
  • Use a requirements.txt file: List dependencies to make reuse easier: 
    numpy==1.26.4
  • Save regularly: Codespaces are temporary; push your code to GitHub to keep it safe.
  • Stop the environment: Check if the environment is running—stop it to reduce hourly credit usage. The environment is saved and consumes fewer resources when stopped.
  • Monitor your Codespaces: You can view all your Codespaces here: https://github.com/codespaces

Useful Resources