title: Where is official documentation for tilde (~) in Pandas?
body: <p>I am pretty sure that <code>~</code> in Pandas is boolean <code>not</code>. I found a couple of StackOverflow questions / answers, but no pointer to official documentation.</p>
  
  <h2>Sanity Check</h2>
  
  <pre><code>#!/usr/bin/env python
  # -*- coding: utf-8 -*-
  
  import pandas as pd
  
  
  df = pd.DataFrame([(1, 2, 1),
                     (1, 2, 2),
                     (1, 2, 3),
                     (4, 1, 612),
                     (4, 1, 612),
                     (4, 1, 1),
                     (3, 2, 1),
                     ],
                    columns=['groupid', 'a', 'b'],
                    index=['India', 'France', 'England', 'Germany', 'UK', 'USA',
                           'Indonesia'])
  
  print(df)
  filtered = df[~(df['a'] == 2)]
  print(filtered)
  </code></pre>
  
  <p>The df is</p>
  
  <pre><code>           groupid  a    b
  India            1  2    1
  France           1  2    2
  England          1  2    3
  Germany          4  1  612
  UK               4  1  612
  USA              4  1    1
  Indonesia        3  2    1
  </code></pre>
  
  <p>and <code>filtered</code> is</p>
  
  <pre><code>         groupid  a    b
  Germany        4  1  612
  UK             4  1  612
  USA            4  1    1
  </code></pre>
  
  <p>So I'm pretty sure it is boolean not.</p>