title: activate venv with pyenv
body: <p>I followed <a href="https://opensource.com/article/19/5/python-3-default-mac" rel="noreferrer">this guide</a> to install <code>pyenv</code> in order to manage all python versions I have installed on my Mac. However, it is not clear to me what the <code>pyenv global 3.7.3</code> command does and how I can activate a venv that uses python 3.7. If I type:</p>
  <pre><code>$ pyenv version
  3.7.3
  </code></pre>
  <p>But apparently this is not enough to activate the venv?</p>