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Multiple Python installations on OS X

Previous versions used homebrew to install the various versions. As suggested in the comments, it's better to use pyenv instead. If you are looking for the previous version of this document, see the revision history.

$ brew update
$ brew install pyenv
$ pyenv install 3.5.0
$ pyenv install 3.4.3
$ pyenv install 3.3.6
$ pyenv install 3.2.6
$ pyenv install 2.7.10
$ pyenv install 2.6.9
$ pyenv versions
* system (set by /Users/bouke/.pyenv/version)
  2.6.9
  2.7.10
  3.2.6
  3.3.6
  3.4.3
  3.5.0

Then, when you need a certain version:

pyenv local 3.5.0

This will create a file .python-version, so pyenv will remember the Python version for this directory. This works also nice with tox, as you can activate many Python version at once. See the pyenv documentation for more information.

See also Using tox and pyenv for testing and development for a more detailed how-to.

@tmehlinger

The Python 3.2 install will fail on newer versions of Homebrew because the formula is incompatible. I had to comment out lines 133-141 of Library/Formula/python3.rb and install Setuptools and Pip manually after the Python install finished.

Other than that, worked perfectly, thanks for taking the time to document this. :)

@IvanExpert

Thanks for this writeup -- very helpful. Also thanks tmhlinger for your tip.

@Bouke
Owner
Bouke commented Apr 7, 2015

The brew versions command has been removed. The instructions are no longer valid.

@zoidbergwill

This worked perfectly for me, I just skipped the brew versions line.

@tdsmith
tdsmith commented Sep 14, 2015

I'm a Homebrew maintainer; I strongly suggest you use pyenv instead if you ever need anything but the most current Python versions. It's a much nicer solution in part because it's designed to handle switching scripts back and forth, which is very difficult for Homebrew to do.

@Bouke
Owner
Bouke commented Sep 18, 2015

Thanks, I didn't know about pyenv, but found very useful already. I've updated the document as this looks like a better way to do this.

@denfromufa

The link is broken:

Using tox and pyenv for testing and development
http://tbb.co/using-tox-and-pyenv-for-testing-and-development/

@denfromufa

I believe the new link is now here:

http://www.holger-peters.de/using-pyenv-and-tox.html

@Bouke
Owner
Bouke commented Sep 28, 2016

Thanks @denfromufa, I've updated the link.

@matinfo
matinfo commented Mar 20, 2017

Good to know, to not use default Python of OSX Sierra:

Add to your shell (~/.bashrc or ~/.zshrc) :

export PATH="/Users/username/.pyenv:$PATH"
eval "$(pyenv init -)"

Remplace username by your MacBook user.
Refresh your terminal env, example: $ source ~/.zshrc (or restart your terminal)

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