title: Do I need to sudo when running pip/easy_install?
body: <p>All of the python tuts I've been reading lately tell me to do things like this:</p>
  
  <pre><code>pip install tornado
  pip install requests
  </code></pre>
  
  <p>And every time I do this I get hit with a <code>permission denied</code> warning. But everything usually works when I <code>sudo</code>. </p>
  
  <p>Is sudo required? And if so, why do so many tutorial instructions fail to mention that? </p>
  
  <p>In ruby we can install using Rbenv or RVM, both of which remove the need to use <code>sudo</code>. Is there any equivalent in python? Or is it implied that you should always <code>sudo</code>?</p>