title: Mac install python3.6 with brew
body: <p>I want to install python version 3.6.
  when I do <code>brew install python</code> it installs latest version of python i.e <code>3.8</code>.</p>
  <p>I tried below solution but it is giving me error.</p>
  <pre><code>brew install --ignore-dependencies https://raw.githubusercontent.com/Homebrew/homebrew-core/f2a764ef944b1080be64bd88dca9a1d80130c558/Formula/python.rb
  </code></pre>
  <p>Error:</p>
  <blockquote>
  <p>Error: Calling Installation of python from a GitHub commit URL is disabled! Use 'brew extract python' to stable tap on GitHub instead.</p>
  </blockquote>
  <p>I even tried solution in <a href="https://stackoverflow.com/questions/51125013/how-can-i-install-a-previous-version-of-python-3-in-macos-using-homebrew">this link</a> but not working.</p>
  <p>Also When I do:</p>
  <pre><code>brew search python
  </code></pre>
  <p>I don't find <code>python@3.6</code> init</p>