Understand environments and packages
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Python has a huge ecosystem of third-party packages—reusable code libraries that extend what Python can do. Before installing packages, it's good practice to set up a virtual environment so that your project's dependencies stay organized and don't interfere with other projects.
What is a virtual environment?
A virtual environment is an isolated folder that contains its own copy of Python and any packages you install. Think of it as a clean workspace for each project—packages you install in one environment don't affect another.
Create a virtual environment
In VS Code, open the integrated terminal (Terminal > New Terminal) and navigate to your project folder. Then run:
python -m venv .venv
This command creates a hidden folder called .venv containing the isolated environment. Activate it with:
| Platform | Command |
|---|---|
| Windows | .venv\Scripts\activate |
| macOS / Linux | source .venv/bin/activate |
When active, you see (.venv) appear at the start of your terminal prompt. You can also use the Python: Select Interpreter command in VS Code to create and activate a virtual environment.
Install packages with pip
pip is Python's built-in package manager. Once your virtual environment is active, use it to install packages:
pip install requests
To see all installed packages in the current environment:
pip list
To save your project's dependencies, so others can recreate the environment:
pip freeze > requirements.txt
And to install from that file:
pip install -r requirements.txt
Tip
VS Code detects your virtual environment automatically. When you open a Python file, look for the Python version in the bottom status bar—select it to choose your .venv environment if it isn't already selected.