Creating a separate environment for a Python project in VS Code is a fundamental best practice that helps you manage dependencies, prevent conflicts, and ensure your projects are portable and reproducible. You should do it almost all the time, but here are the specific “when” and “why” details:

When to Create a Separate Environment

• For Every New Project: The most important rule of thumb is to create a new environment for every new Python project you start. This applies whether it’s a small script or a large application.
• When a Project Has Specific Dependencies: If your project requires a particular version of a library (e.g., pandas==1.5.0) that is different from what another project uses, a separate environment is essential to prevent version conflicts.
• When Collaborating with Others: When working in a team, a separate environment allows you to generate a requirements.txt file (using pip freeze > requirements.txt) that lists all the project’s dependencies and their exact versions. This ensures that every team member can set up an identical environment, eliminating “it works on my machine” issues.
• When Deploying an Application: To deploy a Python application to a server or a container (like Docker), you need a clean, isolated environment with only the necessary packages. A virtual environment makes it easy to specify these dependencies and avoid installing unnecessary libraries.

Why You Should Create a Separate Environment

The core reason for creating a separate environment is dependency isolation.

• Avoids Package Conflicts: Imagine you have two projects. Project A needs django==3.2 and Project B needs django==4.0. If you install them both in your global Python environment, one will overwrite the other, causing one of your projects to break. A separate environment for each project keeps their dependencies completely isolated.
• Reproducibility: A project’s dependencies can change over time. By using a virtual environment and a requirements.txt file, you can “freeze” the exact state of your project’s dependencies at a specific moment. This means you (or anyone else) can recreate the exact same environment a year from now, ensuring the code will still run as intended.
• Keeps Your Global Environment Clean: Your system’s global Python environment should be kept as clean as possible. It often contains packages that are crucial for your operating system or other applications. Installing project-specific libraries directly into the global environment can lead to unexpected errors or even system instability.
• Portability: Virtual environments are not meant to be committed to source control (like Git). Instead, you commit the requirements.txt file. This makes your project lightweight and portable. Anyone can clone your repository and, with a simple command, set up the correct environment on their own machine.

How VS Code Supports Virtual Environments

VS Code has excellent built-in support for Python virtual environments. When you open a project folder, it will often automatically detect existing virtual environments and prompt you to select one. You can also:

• Create a new environment: Use the “Python: Create Environment” command from the Command Palette (Ctrl+Shift+P or Cmd+Shift+P) to quickly create a virtual environment with venv or conda.
• Switch between environments: The status bar at the bottom of the VS Code window shows the currently selected Python interpreter. You can click on it to easily switch to another detected environment.
• Manage packages: The Python extension in VS Code provides tools for managing packages within your active environment.

In summary, creating a separate virtual environment is a simple, non-negotiable step for any serious Python development. It is the best way to ensure your projects are organized, stable, and easy to share with others.

(on Windows) click the Start Menu, and type “PowerShell”, then click Run as administrator:

then use the “cd” command to change directory to the workspace folder. An example:

cd "C:\Users\SlootenvanF\OneDrive - University of Twente\Documents\m5_new\Python\Dashboard\Gapminder"

Make sure to put the complete folder name between quotes! Then run the Activate script again:

.\venv\Scripts\Activate.ps1

If that also does not work for you, try to Google the error and see if you can find a solution for the problem.