code: def stdout(prev, endl='\n', thru=False):
      
      for i in prev:
          sys.stdout.write(str(i) + endl)
          if thru:
              yield i
docs: This pipe read data from previous iterator and write it to stdout.
  
      :param prev: The previous iterator of pipe.
      :type prev: Pipe
      :param endl: The end-of-line symbol for each output.
      :type endl: str
      :param thru: If true, data will passed to next generator. If false, data
                   will be dropped.
      :type thru: bool
      :returns: generator