title: Python Error : No module named pkg_resources
body: <p>I would like to use Python3.7 on MacOS</p>
  
  <p>I already Python 2.7 version.</p>
  
  <p>I created an alias on <code>.bash_profile</code>, <code>alias python="/usr/local/bin/python3.7"</code> then <code>source ~/.bash_profile</code>.</p>
  
  <p>So I deleted Python2.7 to <code>/usr/local/lib/</code></p>
  
  <p>Now, when I try to execute <code>pip install PySide2</code>, I have an error :</p>
  
  <pre><code>Traceback (most recent call last):
    File "/usr/local/bin/pip", line 6, in &lt;module&gt;
      from pkg_resources import load_entry_point
  ImportError: No module named pkg_resources
  </code></pre>
  
  <p>I think this error has happened since I deleted Python2.7</p>
  
  <p>Someone can help me to resolve my error ?</p>
  
  <p>Thank you !</p>