new_contents: # http://www.geeksforgeeks.org/move-zeroes-end-array/
  
  def pushZerosToEnd(arr):
      if not arr: return []
      count = -1
      n = len(arr)
      for i in xrange(n):
          if arr[i] != 0:
              count += 1
              arr[count] = arr[i]
              
      while count + 1 < n:
          count += 1
          arr[count] = 0
  
      return arr
  
  test = [1, 9, 8, 4, 0, 0, 2, 7, 0, 6, 0, 9]
  print pushZerosToEnd(test)
  ~                              
  
subject: Create Shift_zero_to_end.py