title: Joining elements in list of Strings in loop with a condition
body: <p>Every 2 elements should be joined in a loop till the end of the list
  This is what i have been trying to do</p>
  <pre><code>items = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j']
  for i in range(len(items)+1):
    items[i]=items[i]+items[i+1]
    i=i+2
  print(items)
  
  </code></pre>
  <p><strong>Expected Output: ['ab' , 'cd' , 'ef' , 'gh' , 'ij']</strong></p>