Pipenv & Virtual Environments

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This tutorial walks you through installing and using Python packages.

It will show you how to install and use the necessary tools and make strong recommendations on best practices. Keep in mind that Python is used for a great many different purposes, and precisely how you want to manage your dependencies may change based on how you decide to publish your software. The guidance presented here is most directly applicable to the development and deployment of network services (including web applications), but is also very well suited to managing development and testing environments for any kind of project.

Note

This guide is written for Python 3, however, these instructions should work fine on Python 2.7—if you are still using it, for some reason.

☤ Make sure you’ve got Python & pip

Before you go any further, make sure you have Python and that it’s avalable from your command line. You can check this by simply running:

$ python --version

You should get some output like 3.6.2. If you do not have Python, please install the latest 3.x version from python.org or refer to the Installing Python section of The Hitchhiker’s Guide to Python.

Note

If you’re newcomer and you get an error like this:

>>> python
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'python' is not defined

It’s because this command is intended to be run in a shell (also called a terminal or console). See the Python for Beginners getting started tutorial for an introduction to using your operating system’s shell and interacting with Python.

Additionally, you’ll need to make sure you have pip available. You can check this by running:

$ pip --version

If you installed Python from source, with an installer from python.org, or via Homebrew you should already have pip. If you’re on Linux and installed using your OS package manager, you may have to install pip separately.

☤ Installing Pipenv

Pipenv is a dependency manager for Python projects. If you’re familiar with Node.js’ npm or Ruby’s bundler, it is similar in spirit to those tools. While pip can install Python packages, Pipenv is recommended as it’s a higher-level tool that simplifies dependency management for common use cases.

Use pip to install Pipenv:

$ pip install --user pipenv

Note

This does a user installation to prevent breaking any system-wide packages. If pipenv isn’t available in your shell after installation, you’ll need to add the user base’s bin directory to your PATH. You can find the user base by running python -m site which will print site information including the user base. For example, on Linux this will return USER_BASE: '~/.local' so you’ll need to add ~/.local/bin to your PATH. On Linux and macOS you can set your PATH permanently by modifying ~/.profile. On Windows you can set the user PATH permanently in the Control Panel.

☤ Installing packages for your project

Pipenv manages dependencies on a per-project basis. To install packages, change into your project’s directory (or just an empty directory for this tutorial) and run:

$ cd myproject
$ pipenv install requests

Pipenv will install the excellent Requests library and create a Pipfile for you in your project’s directory. The Pipfile is used to track which dependencies your project needs in case you need to re-install them, such as when you share your project with others. You should get output similar to this (although the exact paths shown will vary):

Creating a Pipfile for this project...
Creating a virtualenv for this project...
Using base prefix '/usr/local/Cellar/python3/3.6.2/Frameworks/Python.framework/Versions/3.6'
New python executable in ~/.local/share/virtualenvs/tmp-agwWamBd/bin/python3.6
Also creating executable in ~/.local/share/virtualenvs/tmp-agwWamBd/bin/python
Installing setuptools, pip, wheel...done.

Virtualenv location: ~/.local/share/virtualenvs/tmp-agwWamBd
Installing requests...
Collecting requests
  Using cached requests-2.18.4-py2.py3-none-any.whl
Collecting idna<2.7,>=2.5 (from requests)
  Using cached idna-2.6-py2.py3-none-any.whl
Collecting urllib3<1.23,>=1.21.1 (from requests)
  Using cached urllib3-1.22-py2.py3-none-any.whl
Collecting chardet<3.1.0,>=3.0.2 (from requests)
  Using cached chardet-3.0.4-py2.py3-none-any.whl
Collecting certifi>=2017.4.17 (from requests)
  Using cached certifi-2017.7.27.1-py2.py3-none-any.whl
Installing collected packages: idna, urllib3, chardet, certifi, requests
Successfully installed certifi-2017.7.27.1 chardet-3.0.4 idna-2.6 requests-2.18.4 urllib3-1.22

Adding requests to Pipfile's [packages]...
P.S. You have excellent taste! ✨ 🍰 ✨

☤ Using installed packages

Now that Requests is installed you can create a simple main.py file to use it:

import requests

response = requests.get('https://httpbin.org/ip')

print('Your IP is {0}'.format(response.json()['origin']))

Then you can run this script using pipenv run:

$ pipenv run python main.py

You should get output similar to this:

Your IP is 8.8.8.8

Using $ pipenv run ensures that your installed packages are available to your script. It’s also possible to spawn a new shell that ensures all commands have access to your installed packages with $ pipenv shell.

☤ Next steps

Congratulations, you now know how to install and use Python packages! ✨ 🍰 ✨