title: How to count the frequency of characters in a string in a row?
body: <p><code>input = 'XXYXYYYXYXXYYY'</code></p>
  
  <p>output = <code>[2,1,1,3,1,1,2,3]</code></p>
  
  <p>How would count the number of X's and Y's in a string in the order that they are inputted and then put those values in a list?</p>