pythonmacospython-install

Install mulitple versions of Python 3 on MacOS

I want to have multiple versions of Python 3 on MacOS. For example I need Python3.6 and Python3.7. When using Linux I would simply create an alt install by building Python from source, as follows:

  1. Download the source tarball for a specific Python version and extract
  2. ./configure
  3. sudo make
  4. sudo make altinstall

I will then have a new version of Python installed in usr/local/lib/pythonx.x.

That works perfectly on Linux. How would I go about having access to multiple versions of Python 3 on MacOS?

EDIT: Just to clarify my use case a bit more. I use multiple versions on Python installed on the OS so that I can then use Pipenv for different projects specifying different Python versions.

Solution

  • pyenv is the thing you want. It works very very well:

    pyenv lets you easily switch between multiple versions of Python. It's simple, unobtrusive, and follows the UNIX tradition of single-purpose tools that do one thing well. This project was forked from rbenv and ruby-build, and modified for Python.

    https://github.com/pyenv/pyenv

    Install it via Homebrew:

    $ brew update
$ brew install pyenv

    It handles the download, compilation, and installation of various pythons for you, e.g.:

    $ pyenv install 3.7.2

    It can show you which versions you've installed, and which is active:

    $ pyenv versions
  system
  3.6.7
* 3.7.2

    When you're in a new project directory, just tell pyenv which python version to use there:

    $ pyenv local 3.6.7  # Because e.g. tensorflow isn't compat. with 3.7 :-(

    You can set a 'default' version everywhere else:

    $ pyenv global 3.7.2

    It plays well with pipenv too.