How to Create a Python Virtual Environment

You have a Python project and want its packages kept separate from everything else on the machine. The venv module ships with Python 3, so nothing needs to be installed first.

Create the environment

Open a terminal in the project folder and run:

python3 -m venv .venv

This creates a .venv folder containing a private copy of the Python interpreter and its own site-packages directory. The name .venv is a convention, but any folder name works.

On Windows, use python -m venv .venv.

Activate the environment

source .venv/bin/activate

On Windows (Command Prompt or PowerShell): .venv\Scripts\activate

The prompt changes to show the environment name:

(.venv) $

While the environment is active, python and pip point at the copies inside .venv, not the system versions.

Install packages

pip install requests

Packages land inside .venv and are invisible to other projects. Check what is installed at any time with pip list.

Deactivate when finished

deactivate

The prompt returns to normal and python refers to the system interpreter again. The environment stays on disk. Reactivate it any time with the same source command.

Keep it out of version control. Add .venv/ to the project's .gitignore. The folder is large and specific to one machine. To record what the project depends on instead, run pip freeze > requirements.txt while the environment is active. Anyone can then rebuild the same environment with pip install -r requirements.txt.

If the venv module is missing. On Debian and Ubuntu the module is packaged separately. Install it with sudo apt install python3-venv and run the create command again.