title: Combine string recursive-python
body: <p>I have two string list:
  A = ['YELLOW']
  B = ['BA']</p>
  
  <p>I want to combine these two string using a recursive function to get 
  ['YBAEBALBALBAOBAWBA']</p>
  
  <p>HERE IS my function :</p>
  
  <pre><code>def Combine(A, B):
  
      if len(A) &gt; 0:
          return str(A[0]) + str(B) + Combine(A[:0], B)
  </code></pre>
  
  <p>--
  I have no idea how recursive works?
  Could someone please help me!</p>