macos - How can I install multiple versions of Python on latest OS X and use them in parallel?

Question

I want to run tests with multiple Python versions on OS X 10.11, including:

• Python 2.6 - ?!
• Python 2.7 - default - solved
• Python 3.4 - ?!
• Python 3.5 - installed via brew - works well
• Conda Python 3.5 - ?!

I want to run the tests via tox so tox needs to be able to find them. Sadly it seems that brew doesn't want to install 3.4 since they added 3.5 and I obviously do not want to remove 3.5 one.

Answer 1

This blog post suggests using pyenv with the desired detox. The basic setup with brew requires:

brew install pyenv pyenv-virtualenv pyenv-virtualenvwrapper

Then installing the desired Python versions with pyenv install [version], rather than installing Python using brew. You can check the available versions using pyenv versions.

Finally, pip install detox will ensure you've got tox and detox installed. Then you should be able to specify the desired testing versions in your tox.ini.