title: How do you split a string into a list of strings all of length 3?
body: <p>Stuck on a problem, if I wanted to split a list of characters such as "qwertyzxc" (9 elements) (<code>['q','w','e','r','t','y','z','x','c']</code>) into a list of strings with the length 3. How would I do it?
  Example:</p>
  
  <p>Input : <code>['q','w','e','r','t','y','z','x','c']</code>
  Output : <code>[['q','w','e'],['r','t','y'],['z','x','c']]</code></p>
  
  <p>Thanks, I have been stuck on this for quite a while</p>