Getting started with pipenv

Now that you have a number of Python projects you are starting to realize, package conflicts are inevitable. You are left to wonder how to prevent this problem. You may have seen tutorials asking for you to “pipenv install pipfile” leaving you frustrated as you are not familiar with this way of working, regardless of the reason, perhaps it is time to start using “pipenv”

• Environment: Windows 10
• Editor: Visual Studio Code

These instructions are compatible with other Operating Systems and IDEs

Table of contents

If you are not interested in the history of package management and would like to just install pipenv, then skip to Introducing pipenv

• Getting started with pipenv
  • Table of contents
  • pipenv benefits
  • Python Packaging History
    • Then: came easy_install
    • Later: pip, virtualenv and requirements.txt
    • The new: pipfile standard
  • Introducing pipenv
    • Install pipenv
    • pipenv –help

pipenv benefits

pipenv was developed by Kenneth Reitz (@kennethreitz) as a temporary solution until the new pip specs are integrated

• Recommended by Python.org
• Easy to mage work environments
• Easy to share work environments
• Version integrity and control

Python Packaging History

It isn’t required to understand the history of package management in order to use pipenv. I am only giving a little background into what’s behind the effort, eventually pipenv should be integrated into pip (or become pip)

Historically the way Python managed packages was not ideal. After installing python, the user would have to download a zip file containing the package, unzip it, run “setup install”. Or open the archive, copying the zip contents into the side packages folder, an inconvenience.

At the time PyPi was just an index of packages with links to where users could download the zip files. Now a days, when a package is registered, it must be uploaded to the website.

At the time all versions of Python were globally installed including the packages, this meant the user could not have two versions of a package. It also meant, if you developed an application using X version of a package, and needed to develop a new application using N version of that same package, it could potentially brake your code. As developers grew their environments, it would become more difficult to manage packages.

Then: came easy_install

The user would just type easy_install the name of the package, the script would go to PyPi and look for it on the index and get the URL from where to downloaded. it didn’t have an uninstall option and the integrity of the link depended on the publishers

Later: pip, virtualenv and requirements.txt

• virtualenv a virtual environment tool became popular to manage different development environments to host different instances of Python and required packages, now you could have multiple versions of packages running with out conflicting with one another, thus protecting the integrity of other projects

• requirements.txt became the file listing all the required resources for each virtualenv

• pip is an improvement over easy_install, as it has more command options for managing Python packages, Resolves, Downloads, Installs and Uninstalls Python packages. It uses the requirements.txt and it can manipulate virtual environments, so pip became the standard

Python had no lock-file, as found in other development communities, such as PHP, Ruby and Rust. Although package management had grown, it continue to have its shared of headaches due to a lack of lock-files. Although the requirements.txt filled much of the lock-file role, the other two tools, pip and virtualenv, did not have a seamless integration. Later, pip-tools was developed to integrate these tools, but again, they where all developed individually and each had their shortcomings, trying to update one could brake the others.

The new: pipfile standard

• Pipfile replaces requirements.txt
• Uses the TOML file format
• It includes two groups [[packages]] and [[dev-packages]]
• Pipfile will eventually be integrated into pip

Sample of a Pipfile

[[source]]
name = "pypi"
url = "https://pypi.org/simple"
verify_ssl = true

[dev-packages]

[packages]
spacy = "*"

[requires]
python_version = "3.6"

When the Pipfile is processed, it generates Pipfile.lock, it adds the following:

• Two groups, “default” and “develop”
• It contains all the dependencies, including version numbers and hashes for each entry.
• The file will be formated in JSON for easy machine parsing

Sample file block of Pipfile.lock

{
    "_meta": {
        "hash": {
            "sha256": "19470a7a59afe1a70019f1dcb8c49c85ef5b22dcd5b8e35dc1669444376d88dd"
        },
        "pipfile-spec": 6,
        "requires": {
            "python_version": "3.6"
        },
        "sources": [
            {
                "name": "pypi",
                "url": "https://pypi.org/simple",
                "verify_ssl": true
            }
        ]

Introducing pipenv

It integrates pipfile, pipfile.lock, pip and virtualenv in a seamless package automating the virtual environment. It also allows for hash authentication upon installation. It is the Official recommendation by python.org

Pipenv Screencast by Kenneth Reitz

Install pipenv

Use pip to install pipenv. before installing it, you should update your version of pip

• pip install --upgrade pip
• In Windows > python -m pip install --upgrade pip

1. Install pipenv:
   • > pip install pipenv
2. Create a new project folder (Windows):
   • > md new_project
3. Navigate to the new folder
   • > cd new_project
4. Create a new pipenv in the new folder
   • > pipenv --python 3.6 # or what ever version
   • This will create all the necessary files
5. Launch a subshell in pipenv
   • > pipenv shell
   • This will run pipenv version of Python
6. Install a new package in new_project
   • > pipenv install <package_name>
   • This will update the Pipfile and Pipfile.lock

I assume you are relatively new to Python, and if you are not familiar with pipenv, I recommend you to familiarize with this process, as you move forward it will become a requirement for developing new projects and sharing them.

This blog is a quick pipenv introduction, getting you up and running as fast as possible with this flexible tool. For a comprehensive list of commands and full documentation please visit:

• Official website: https://pipenv.readthedocs.io/en/latest/
• Github repo: https://github.com/pypa/pipenv
• Kenneth Reitz vimo: https://vimeo.com/kennethreitz

Thank you

Enrique Bruzual

pipenv –help

A copy of pipenv help file for your convenience

pipenv --help
Usage: pipenv [OPTIONS] COMMAND [ARGS]...

Usage Examples:

   Create a new project using Python 3.7, specifically:
   $ pipenv --python 3.7

   Remove project virtualenv (inferred from current directory):
   $ pipenv --rm

   Install all dependencies for a project (including dev):
   $ pipenv install --dev

   Create a lockfile containing pre-releases:
   $ pipenv lock --pre

   Show a graph of your installed dependencies:
   $ pipenv graph

   Check your installed dependencies for security vulnerabilities:
   $ pipenv check

   Install a local setup.py into your virtual environment/Pipfile:
   $ pipenv install -e .

   Use a lower-level pip command:
   $ pipenv run pip freeze