Say Goodbye to Virtualenv

These days it’s hard to imagine developing in Python without virtualenv. Having isolated environments prevents a whole class of subtle (and not so subtle) bugs, and makes it much easier to manage dependencies.

But virtualenv isn’t without it’s pain points. Having to activate and deactivate is a nuisance (virtualenvwrapper helps a bit) that makes jumping into, out of, and between environments harder than it needs to be. Ideally we should be able to pip install django and ./ runserver without thinking about anything else.

The solution is pipenv. pipenv is a replacement for both pip and virtualenv, and is going to let us say goodbye to activate/deactivate forever.

I’m not going to cover it in detail for this post, but in addition to abstracting away virtual environments, pipenv also gives us a replacement for requirements.txt that ensures we get deterministic builds. Learn more about what they look like here.

Installing pipenv

For macOS users, the easiest way to get started is with homebrew:

$ brew install pipenv

But you can always use pip:

$ pip install pipenv

Now that we have pipenv installed, create a directory for your project:

$ mkdir -p ~/projects/pipenv_test/ && cd ~/projects/pipenv_test/

Using pipenv

Here’s where the magic starts. Let’s install a dependency:

$ pipenv install django

That’s it. Behind the scenes pipenv has created a virtual environment and installed django into it. It has also recorded django as a dependency in Pipfile and Pipfile.lock. Again, we won’t go into those files in depth here, but like requirements.txt they should go into version control.

Continuing with our django example, let’s create a project:

$ pipenv run startproject pipenvtest

So what exactly is happening here? By prefixing our normal command with pipenv run, it will be run within the context of the virtual environment that we are no longer thinking about.

Now we can start the dev server:

$ cd pipenvtest
$ pipenv run ./ runserver

Silky smooth. What’s a virtual environment?

Environment Variables

If you’re doing things by the book then you’re probably storing your various secrets/tokens/etc in environment variables. The problem is when you execute pipenv run ... it’s going to lose those environment variables. Fixing that is as easy as adding a .env file to the root of your project (aka next to Pipfile) and populating it with your vars:

$ echo 'DATABASE_PASSWORD=supersecretstuff' >> .env

Now when you pipenv run ... those environment variables will be in context.

That’s it! Enjoy never thinking about virtualenv again.