title: Pip is not linking to my upgraded Python version. Package python3-pip is not available, but is referred to by another package
body: <p>Having issues linking pip to python 3.7. Both pip and pip3 been installed but linking to Python 2.7. </p>
  
  <p>I have tried to reinstall Python3 and then pip no progress. </p>
  
  <p>I get the following message:</p>
  
  <blockquote>
    <p>Package python3-pip is not available, but is referred to by another package.</p>
  </blockquote>
  
  <p>This may mean that the package is missing, has been obsoleted, or
  is only available from another source</p>
  
  <pre class="lang-sh prettyprint-override"><code>$ python --version
  Python 3.7.4
  
  $ pip -V
  /usr/local/lib/python2.7/dist-packages/pip/_vendor/requests/__init__.py:83: RequestsDependencyWarning: Old version of cryptography ([1, 2, 3]) may cause slowdown.
    warnings.warn(warning, RequestsDependencyWarning)
  pip 19.2.1 from /usr/local/lib/python2.7/dist-packages/pip (python 2.7)
  
  $ pip3 -V
  /usr/local/lib/python2.7/dist-packages/pip/_vendor/requests/__init__.py:83: RequestsDependencyWarning: Old version of cryptography ([1, 2, 3]) may cause slowdown.
    warnings.warn(warning, RequestsDependencyWarning)
  pip 19.2.1 from /usr/local/lib/python2.7/dist-packages/pip (python 2.7)
  
  
  $ sudo apt-get install python3-pip
  [sudo] password for TarikDev: 
  Reading package lists... Done
  Building dependency tree       
  Reading state information... Done
  Package python3-pip is not available, but is referred to by another package.
  This may mean that the package is missing, has been obsoleted, or
  is only available from another source
  
  E: Package 'python3-pip' has no installation candidate
  </code></pre>