title: How to leave/exit/deactivate a Python virtualenv
body: <p>I'm using virtualenv and the virtualenvwrapper. I can switch between virtualenv's just fine using the <code>workon</code> command.</p>
  <pre><code>me@mymachine:~$ workon env1
  (env1)me@mymachine:~$ workon env2
  (env2)me@mymachine:~$ workon env1
  (env1)me@mymachine:~$ 
  </code></pre>
  <p>How do I exit all virtual environments and work on my system environment again? Right now, the only way I have of getting back to <code>me@mymachine:~$</code> is to exit the shell and start a new one. That's kind of annoying. Is there a command to work on &quot;nothing&quot;, and if so, what is it? If such a command does not exist, how would I go about creating it?</p>