title: jupyter notebook bad interpreter error message
body: <p>I tried to use jupyter notebook with kernel python3, but I got this error message.</p>
  
  <pre><code>anonymous$ jupyter notebook
  /usr/local/opt/python/bin/python2.7: bad interpreter: No such file or directory
  </code></pre>
  
  <p>Information about python and pip installed on mac (i used pip3 to install jupyter ):</p>
  
  <pre><code>anonymous$ which -a python python2 python2.7 python3 python3.6
  /usr/bin/python
  /usr/bin/python2.7
  /usr/local/bin/python3
  /usr/local/bin/python3.6
  anonymous$ which -a pip pip2 pip3
  /usr/local/bin/pip
  /usr/local/bin/pip3
  </code></pre>
  
  <p>Tried to solve it with "brew update &amp;&amp; brew upgrade jupyter" as the other post suggested but did not work. Got an error message saying that "Error: jupyter not installed".</p>