Python的多線程參數錯誤

Question

我剛開始用多線程，所以我想我會做我自己一個小而簡單的例子：

import time 
import threading 

def count(who): 
     count = 1 
     while count <= 5: 
       print who + " counted to: " + str(count) 
       time.sleep(0.1) 
       count += 1 

thread1 = threading.Thread(target=count, args=('i')) 
thread1.start() 

偉大的工程，並打印出以下幾點：

>>> i counted to: 1 
>>> i counted to: 2 
>>> i counted to: 3 
>>> i counted to: 4 
>>> i counted to: 5 

奇怪的是但是，當我想參數更改爲另一個名字： 「約翰」：

線程1 = threading.Thread（目標=算，ARGS =（ '約翰'））

希望它會產生：

>>> john counted to: 1 
>>> john counted to: 2 
>>> john counted to: 3 
>>> john counted to: 4 
>>> john counted to: 5 

然而，procudes錯誤：

Exception in thread Thread-1: 
Traceback (most recent call last): 
    File "/usr/lib/python2.7/threading.py", line 810, in __bootstrap_inner 
    self.run() 
    File "/usr/lib/python2.7/threading.py", line 763, in run 
    self.__target(*self.__args, **self.__kwargs) 
TypeError: count() takes exactly 1 argument (4 given) 

我真的不知道這裏發生了什麼？有誰知道？

Answer 1

添加一個逗號，清楚你想要一個元組：

thread1 = threading.Thread(target=count, args=('john',)) 

目前蟒蛇認爲括號是多餘的，所以("john")計算爲"john"這四個字符，所以你得到的消息。