import commands
import threading

class Idletime(threading.Thread):
    def run(self):
        idle=commands.getoutput('xprintidle')
        time.sleep(5)
    def getidletime():
        return idle

Traceback (most recent call last):
  File "<pyshell#10>", line 1, in <module>
    test.start()
TypeError: unbound method start() must be called with Idletime instance as first argument (got nothing instead)

test = Idletime()
test.start()