virtual env reference

What is a virtual environment?

In Python, a virtual environment lets you install packages in an isolated location – usually for a specific application – instead of globally. This lets each application have its own isolated environment with only the packages it needs.

Managing virtual environments with a requirements.txt file

It seems like Pipenv is the best approach for python package management. But lots of projects still manage virtual environments using a workflow like this:

• Activate a virtual env when working on a project.
• Install packages using pip install <package>.
• Update requirements.txt using pipreqs or pip freeze.
• Commit updates to requirements.txt.
• Activate different virtual env when working on a different project.

Recipes

Make sure you’ve installed virtualenv globally with pip install virtualenv.

Create virtual env

python -m virtualenv <name>

Activate venv

source <name>bin/activate

Deactivate venv

If you’ve already activated a venv, you’ll have access to the deactivate command:

deactivate

Other notes

• When you activate a virtual env, it seems like the virtual env’s bin directory gets added to your path. This is why you have access to commands like deactivate (which lives at <venv-path>/bin/deactivate.

Sources

• venv – Python docs