title: Pandas Select Rows from a dataframe with highest value within a category in separate column
body: <p>I am looking for a way of selecting the rows of a dataframe with the highest value within a group identified in a separate column.</p>
  <p>DataFrame:</p>
  <pre><code>  Group     Value
  0  A         0
  1  A         12
  2  A         22
  3  A         63
  4  B         0
  5  B         24
  6  B         66
  7  B         78
  </code></pre>
  <p>Desired DataFrame:</p>
  <pre><code>  Group     Value
  0  A         63
  1  B         78
  
  </code></pre>