def isReadable(poller):
 for fdmask in poller.poll(0):
  mask = fdmask[1]
  if (mask & POLLIN):
   return True

def isReadable ( poller ) : for fdmask in poller . poll ( 0 ) : mask = fdmask [ 1 ] if ( mask & POLLIN ) : return True
check whether a poll object has a readable fd .