title: Filter dataframe value
body: <p>I have a dataframe that I want to filter by value more than 20</p>
  
  <pre><code>ID   value
  A    10
  B    21
  C    22
  </code></pre>
  
  <p>I used <code>df['ID'] &gt; 20</code> and received result </p>
  
  <pre><code>False
  True
  True
  </code></pre>
  
  <p>However, I want it to return <code>B, C</code>, not boolean value</p>