title: module 'pip' has no attribute 'pep425tags'
body: <p>When I am trying to install .whl with pip</p>
  <p>it said:</p>
  <pre><code>... is not a supported wheel on this platform
  </code></pre>
  <p>to solve this problem, I searched the Internet and it said I can input this into repl</p>
  <pre><code>import pip; print(pip.pep425tags.get_supported())
  </code></pre>
  <p>with this I can see the tags and versions that pip supports</p>
  <p>However, when I input this code, it said:</p>
  <pre><code>AttributeError: module 'pip' has no attribute 'pep425tags'
  </code></pre>
  <p>What's wrong?</p>
  <p>(pip 10.0.1 on python 3.6)</p>