python类实例化中，这个字符串参数是怎么回事？

在学习多线程的时候看到这么一个列子。

#!/usr/local/bin/python
#coding=utf-8
import random,threading,time
from Queue import Queue
#Producer thread
class Producer(threading.Thread):
    def __init__(self, t_name, queue):
        threading.Thread.__init__(self,name=t_name)
        self.data=queue
    def run(self):
        for i in range(10):#随机产生10个数字 ，可以修改为任意大小
            randomnum=random.randint(1,99)
            print "%s: %s is producing %d to the queue!" % (time.ctime(), self.getName(), randomnum)
            self.data.put(randomnum) #将数据依次存入队列
            time.sleep(1)
        print "%s: %s finished!" %(time.ctime(), self.getName())

#Consumer thread
class Consumer_even(threading.Thread):
    def __init__(self,t_name,queue):
        threading.Thread.__init__(self,name=t_name)
        self.data=queue
    def run(self):
        while 1:
            try:
                val_even = self.data.get(1,5) #get(self, block=True, timeout=None) ,1就是阻塞等待,5是超时5秒
                if val_even%2==0:
                    print "%s: %s is consuming. %d in the queue is consumed!" % (time.ctime(),self.getName(),val_even)
                    time.sleep(2)
                else:
                    self.data.put(val_even)
                    time.sleep(2)
            except:#等待输入，超过5秒 就报异常
                print "%s: %s finished!" %(time.ctime(),self.getName())
                break
class Consumer_odd(threading.Thread):
    def __init__(self,t_name,queue):
        threading.Thread.__init__(self, name=t_name)
        self.data=queue
    def run(self):
        while 1:
            try:
                val_odd = self.data.get(1,5)
                if val_odd%2!=0:
                    print "%s: %s is consuming. %d in the queue is consumed!" % (time.ctime(), self.getName(), val_odd)
                    time.sleep(2)
                else:
                    self.data.put(val_odd)
                    time.sleep(2)
            except:
                print "%s: %s finished!" % (time.ctime(), self.getName())
                break
#Main thread
def main():
    queue = Queue()
    producer = Producer('Pro.', queue)
    consumer_even = Consumer_even('Con_even.', queue)
    consumer_odd = Consumer_odd('Con_odd.',queue)
    producer.start()
    consumer_even.start()
    consumer_odd.start()
    producer.join()
    consumer_even.join()
    consumer_odd.join()
    print 'All threads terminate!'

if __name__ == '__main__':
    main()

其中Producer类实例化的时候producer = Producer('Pro.', queue)
第一个参数居然是个字符串。。初学的我表示不懂。。
这个是怎么回事，是谁处理了这个字符串？？

---

def __init__(self, t_name, queue):

    threading.Thread.__init__(self,name=**t_name**)
    self.data=queue
    

实例化的时候python会交给__init__处理，第一个参数会赋值给t_name，所以这个字符串也就是给Thread起了个名字

---

name传到了threading.Thread的__init__方法中，name就是指thread的名字。name is the thread name. By default, a unique name is constructed of the form “Thread-N” where N is a small decimal number.args is the argument tuple for the target invocation. Defaults to ().