title: Python:Change pip path
body: <p>I install py3.6 in dir <em>A</em> but later I install py3.7 in dir <em>B</em>. But I prefer to use py3.7 so I replace the whole dir <em>A</em> with dir <em>B</em>(<em>A</em> is filled with py3.7 and <em>B</em> does not exist anymore).<br>
  Now, my pip is using path:<em>B</em> but it does not exist anymore so I need to change it.<br>
  <strong><em>HELP!</em></strong></p>
  
  <p><strong>Edit:</strong></p>
  
  <p>I use</p>
  
  <pre><code>python -m pip uninstall pip
  </code></pre>
  
  <p>and install it again with easy_install 
  <strong><em>BUT</em></strong> now it said something cannot <em>import main</em></p>