Python kill process

import osimport threadingimport timeimport subprocessclass R(threading.Thread):    def __init__(self, cmd):        threading.Thread.__init__(self)        self.cmd = cmd        self.flag = False        self.pro = subprocess.Popen(self.cmd)            def setFlag(self, f):        self.flag = f    def run(self):        while True:            if self.pro == None:                break            elif self.flag:                self.pro.kill()                break        def p(cmd):    #t = os.popen(cmd).read()    t = subprocess.Popen(['java', 'T'])    print t    def f():    t1 = time.time()    print '0000000000'    t = threading.Thread(target=p, args=('java T',))    t.start()    print '1111111111'    time.sleep(2)    t2 = time.time()    t0 = t2 - t1    def f2():    cmd = ['java', 'T']    r = R(cmd)    r.start()    time.sleep(2)    r.setFlag(True)if __name__ == '__main__':    f2()