class MyThread(threading.Thread):
    myStr = ""
    def run(self):
        for i in count(1):
            print "hello" + self.myStr
//...
MyThread().start()

class MyThread(threading.Thread):
    def __init__(myStr):
        self.myStr = myStr

    def run(self):
        for i in count(1):
            print "Hello " + self.myStr

MyThread("sample string").start()

def run(s):
        for i in count(1):
            print "Hello " + s
t = Thread(target=run, args=["string"])
t.start()