question: set the stdin of the process 'grep f' to be b'one\ntwo\nthree\nfour\nfive\nsix\n'
  
target: p = Popen ( [ 'grep' , 'f' ] , stdout = PIPE , stdin = PIPE , stderr = STDOUT ) grep_stdout = p . communicate ( input = 'one\ntwo\nthree\nfour\nfive\nsix\n' ) [ 0 ] 
  