title: Switching between Python 3.7 and 3.8 under Anaconda
body: <p>I have an Anaconda installation on Windows 10 primarily to run Jupyter Notebook and Spyder.</p>
  <p>I find the Python runtime (python.exe) in 3 places after installation, viz:</p>
  <ol>
  <li><code>D:\ProgramData\Anaconda3</code></li>
  <li><code>D:\ProgramData\Anaconda3\pkgs\python-3.7.6-h60c2a47_2</code></li>
  <li><code>D:\ProgramData\Anaconda3\pkgs\python-3.8.2-he1778fa_13</code></li>
  </ol>
  <p>The python.exe under 1. and 2. are identical and run <em>Python 3.7</em>. 3. runs <em>Python 3.8</em>.</p>
  <p>Questions:</p>
  <ol>
  <li><p>What is the rationale of having two versions under <strong>pkgs</strong> (as in 2. and 3. above) but just one default version (as in 1.)?</p>
  </li>
  <li><p>The contents under the <strong>pkgs</strong> directory - are they complete Python installations?</p>
  </li>
  <li><p>What is the best way to make <strong>Jupyter Notebook</strong> pickup <em>Python 3.8</em>? It currently picks up <em>Python 3.7</em> because the location 1. is in PATH. (That is, are the <strong>pkgs</strong> directories full installations)?</p>
  </li>
  <li><p>If I want to work with <em>Python 3.9</em>, is there a way to upgrade the current <strong>Ananconda</strong> to that extent? Or, do I have to delete the current Ananconda3 and install the latest Anaconda <strong>provided, of course</strong> it supports <em>Python 3.9</em>?</p>
  </li>
  </ol>