title: AttributeError: 'NoneType' object has no attribute 'loader'
body: <p>having an issue today when I started up my laptop (Ubuntu 18.4) and trying to use pip to install packages, I'm met with this error:</p>
  
  <pre><code>Error processing line 3 of /home/cjones/.local/lib/python3.6/site-packages/googleapis_common_protos-1.5.8-py3.6-nspkg.pth:
  
    Traceback (most recent call last):
      File "/usr/lib/python3.6/site.py", line 174, in addpackage
        exec(line)
      File "&lt;string&gt;", line 1, in &lt;module&gt;
      File "&lt;frozen importlib._bootstrap&gt;", line 568, in module_from_spec
    AttributeError: 'NoneType' object has no attribute 'loader'
  
  Remainder of file ignored
  </code></pre>
  
  <p>I don't think I changed anything since last successful boot but it seems as though something is missing... can anyone help?</p>