new_contents: #!/usr/bin/env python3
  '''
  This file is to learn about loop more detail.
  '''
  l1 = [1,3,4]
  # for in
  for item in l1:
      print(item)
  
  # break
  l2 = list(range(1,10))
  for i in l2:
      print("current value is %d",i)
      if i == 5 :
          print("break loop when i equals 5")
          break
  
  # while
  l3 = ["a","b","d"];
  i = 0
  while i<len(l3):
      print(l3[i])
      i = i + 1 
  
  # continue
  l4 = [1,2,3,4,5]
  index = 0
  for (l,index )in l4 :
      if index == 2:
          continue
      print("current value is %d",index)
      index = index + 1
subject: add loop