title: Pandas groupby to find percent True and False
body: <p>I have a column of sites: ['Canada', 'USA', 'China' ....]</p>
  
  <p>Each site occurs many times in the SITE column and next to each instance is a true or false value.</p>
  
  <pre><code>INDEX | VALUE | SITE
  
  0     | True  | Canada
  1     | False | Canada
  2     | True  | USA
  3     | True  | USA
  </code></pre>
  
  <p>And it goes on. </p>
  
  <p><strong>Goal 1: I want to find, for each site, what percent of the VALUE column is True.</strong></p>
  
  <p><strong>Goal 2: I want to return a list of sites where % True in the VALUE column is greater than 10%.</strong> </p>
  
  <p>How do I use groupby to achieve this? I only know how to use groupby to find the mean for each site which won't help me here.</p>