title: In pandas, how to perform value counts of gender(or any categorical variable) based on another categorical column?
body: <p>I have a dataframe like below: </p>
  
  <pre><code>gender   doctor name
  female       A
   male        B
   male        A
  female       C
  female       B
  </code></pre>
  
  <p>How to do value counts of gender based on doctor's name?</p>