title: Warning: pip is being invoked by an old script wrapper
body: <blockquote>
    <p>WARNING: pip is being invoked by an old script wrapper. This will fail
    in a future version of pip. Please see
    <a href="https://github.com/pypa/pip/issues/5599" rel="noreferrer">https://github.com/pypa/pip/issues/5599</a> for advice on fixing the
    underlying issue. To avoid this problem you can invoke Python with '-m
    pip' instead of running pip directly.</p>
  </blockquote>
  
  <p>When I directly type <code>pip list</code> to the terminal, I get the above warning. What does it mean exactly? </p>
  
  <p>Should I always use it as <code>python3 -m pip list</code>? If I use it in that way, same output (list of packages) comes up without any warning.</p>
  
  <p>p.s. : I am on ubuntu 18.10</p>