# Virtualenv

## Why Use Virtualenv?

You should use Virtualenv because:

- It allows you to install multiple versions of the same dependency.

- If you have an operating system version of Python, it prevents you from changing its dependencies and potentially messing up your os.

## How to Use Virtualenv

Create your project folder, then a virtualenv within it:

    $ mkdir myproject
    $ cd myproject
    $ python3 -m venv .venv

Now, whenever you want to work on a project, you only have to activate the corresponding environment.

    $ . .venv/bin/activate
    (venv) $

    > .venv\scripts\activate
    (venv) >

You are now using your virtualenv (notice how the prompt of your shell has changed to show the active environment).

To install packages in the virtual environment:

    $ pip install click

And if you want to stop using the virtualenv, use the following command:

    $ deactivate

After doing this, the prompt of your shell should be as familiar as before.