title: Python : How can I get Rows which have the max value of the group to which they belong?
body: <p>I reword my question. I'm searching solution for the following problem:</p>
  
  <p>I have a dataFrame like:</p>
  
  <pre><code>   Sp   Mt   Value  count
  4  MM2  S4   bg     10
  5  MM2  S4   dgd    1
  6  MM4  S2   rd     2
  7  MM4  S2   cb     8
  8  MM4  S2   uyi    8
  </code></pre>
  
  <p>My objective is to get ALL the rows where count equal max in each group e.g. :</p>
  
  <pre><code>MM4  S4   bg     10
  MM4  S2   cb     8
  MM4  S2   uyi    8
  </code></pre>
  
  <p>I group by ['Sp','Mt']</p>
  
  <p>Somebody knows how can I do it in pandas or in python?</p>