[python] Why use pip over easy_install?

A tweet reads:

Don't use easy_install, unless you like stabbing yourself in the face. Use pip.

Why use pip over easy_install? Doesn't the fault lie with PyPI and package authors mostly? If an author uploads crap source tarball (eg: missing files, no setup.py) to PyPI, then both pip and easy_install will fail. Other than cosmetic differences, why do Python people (like in the above tweet) seem to strongly favor pip over easy_install?

(Let's assume that we're talking about easy_install from the Distribute package, that is maintained by the community)

UPDATE: setuptools has absorbed distribute as opposed to the other way around, as some thought. setuptools is up-to-date with the latest distutils changes and the wheel format. Hence, easy_install and pip are more or less on equal footing now.

Source: http://pythonhosted.org/setuptools/merge-faq.html#why-setuptools-and-not-distribute-or-another-name

Just met one special case that I had to use easy_install instead of pip, or I have to pull the source codes directly.

For the package GitPython, the version in pip is too old, which is 0.1.7, while the one from easy_install is the latest which is 0.3.2.rc1.

I'm using Python 2.7.8. I'm not sure about the underlay mechanism of easy_install and pip, but at least the versions of some packages may be different from each other, and sometimes easy_install is the one with newer version.

easy_install GitPython

Two reasons, there may be more:

1. pip provides an uninstall command

2. if an installation fails in the middle, pip will leave you in a clean state.

Another—as of yet unmentioned—reason for favoring pip is because it is the new hotness and will continue to be used in the future.

The infographic below—from the Current State of Packaging section in the The Hitchhiker's Guide to Packaging v1.0—shows that setuptools/easy_install will go away in the future.

Here's another infographic from distribute's documentation showing that Setuptools and easy_install will be replaced by the new hotness—distribute and pip. While pip is still the new hotness, Distribute merged with Setuptools in 2013 with the release of Setuptools v0.7.

As an addition to fuzzyman's reply:

pip won't install binary packages and isn't well tested on Windows.

As Windows doesn't come with a compiler by default pip often can't be used there. easy_install can install binary packages for Windows.

Here is a trick on Windows:

• you can use easy_install <package> to install binary packages to avoid building a binary

• you can use pip uninstall <package> even if you used easy_install.

This is just a work-around that works for me on windows. Actually I always use pip if no binaries are involved.

See the current pip doku: http://www.pip-installer.org/en/latest/other-tools.html#pip-compared-to-easy-install

I will ask on the mailing list what is planned for that.

Here is the latest update:

The new supported way to install binaries is going to be wheel! It is not yet in the standard, but almost. Current version is still an alpha: 1.0.0a1

https://pypi.python.org/pypi/wheel

http://wheel.readthedocs.org/en/latest/

I will test wheel by creating an OS X installer for PySide using wheel instead of eggs. Will get back and report about this.

cheers - Chris

A quick update:

The transition to wheel is almost over. Most packages are supporting wheel.

I promised to build wheels for PySide, and I did that last summer. Works great!

HINT: A few developers failed so far to support the wheel format, simply because they forget to replace distutils by setuptools. Often, it is easy to convert such packages by replacing this single word in setup.py.

REQUIREMENTS files.

Seriously, I use this in conjunction with virtualenv every day.

QUICK DEPENDENCY MANAGEMENT TUTORIAL, FOLKS

Requirements files allow you to create a snapshot of all packages that have been installed through pip. By encapsulating those packages in a virtualenvironment, you can have your codebase work off a very specific set of packages and share that codebase with others.

From Heroku's documentation https://devcenter.heroku.com/articles/python

You create a virtual environment, and set your shell to use it. (bash/*nix instructions)

virtualenv env
source env/bin/activate

Now all python scripts run with this shell will use this environment's packages and configuration. Now you can install a package locally to this environment without needing to install it globally on your machine.

pip install flask

Now you can dump the info about which packages are installed with

pip freeze > requirements.txt

If you checked that file into version control, when someone else gets your code, they can setup their own virtual environment and install all the dependencies with:

pip install -r requirements.txt

Any time you can automate tedium like this is awesome.

pip won't install binary packages and isn't well tested on Windows.

As Windows doesn't come with a compiler by default pip often can't be used there. easy_install can install binary packages for Windows.

From Ian Bicking's own introduction to pip:

pip was originally written to improve on easy_install in the following ways

• All packages are downloaded before installation. Partially-completed installation doesn’t occur as a result.
• Care is taken to present useful output on the console.
• The reasons for actions are kept track of. For instance, if a package is being installed, pip keeps track of why that package was required.
• Error messages should be useful.
• The code is relatively concise and cohesive, making it easier to use programmatically.
• Packages don’t have to be installed as egg archives, they can be installed flat (while keeping the egg metadata).
• Native support for other version control systems (Git, Mercurial and Bazaar)
• Uninstallation of packages.
• Simple to define fixed sets of requirements and reliably reproduce a set of packages.