input: 
  def get_greatest_2(items):
      """
      Given a list of integers, find and return the greatest two numbers.
      Example:
      >>> myList = [1, 5, 3, 7, 4, 7, 8, 9, 2, 10, 6, 8]
      >>> get_greatest_2(myList)
      (10, 9)
      """
      max1 = max2 = float('-inf')
      for item in items:
          if item > max1:
              max1, max2 = item, max1
          elif item > max2:
              max2 = item
      return max1, max2
  
output:     max1 = max2 = float('-inf')
      for item in items:
          if item > max1:
              max1, max2 = item, max1
          elif item > max2:
              max2 = item
      return max1, max2