title: calculate length of list recursively
body: <p>If you have a list = [1,2,3,4,5]</p>
  
  <p>how would you recursively calculate the length of that list without using len(list)?</p>
  
  <pre><code>myarray = [1,2,3,4,5]
  
  def mylist(myarray):
      if (myarray == []):
          print ("The list is empty")
          return 
      return 1 + ?
  </code></pre>
  
  <p>Don't want to use len but just add 1 each time there exists a value in list. How would I do that?</p>