<p><code>pyenv</code> for multiple Python installations on OS X. </p>
<pre><code>$ 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
</code></pre>
<p>Then, when you need a certain version:</p>
<pre><code>pyenv local 3.5.0
</code></pre>
<p>This will create a file <code>.python-version</code>, so pyenv will remember the Python version for this directory.</p>