蟒蛇線程（join（）方法而不是等待線程結束？）

Question

import time 
from threading import Thread 

def s_process(): 
    print('***********************************************') 
    ##time.sleep(2) 
    print('###############################################') 
    ##time.sleep(2) 
    return 

a = Thread(target=s_process) 

while(True): 
    a.start() 
    a.join() 
    a.start() 
    a.join() 

爲什麼這個代碼導致錯誤

*********************************************** 
############################################### 
Traceback (most recent call last): 
    File "xxxxxxxxxxxxxxxxxxxxx", line 16, in <module> 
    a.start() 
RuntimeError: threads can only be started once 

應該不會加入（）等到線程完成。如果我有誤解怎麼加入（）的作品，我應該如何等待線程不使用超時

Answer 1

完成這應該工作：

import time 
from threading import Thread 

def s_process(): 
    print('***********************************************') 
    ##time.sleep(2) 
    print('###############################################') 
    ##time.sleep(2) 
    return 

while(True): 
    a = Thread(target=s_process) 
    a.start() 
    a.join() 
    del a   #deletes a 

Answer 2

要啓動多個線程，建立threading.Thread對象的列表和使用for圈像這樣重申他們start()和join()方法：

import time 
from threading import Thread 

def s_process(): 
    print('***********************************************') 
    time.sleep(2) 
    print('###############################################') 
    time.sleep(2) 
    return 

# list comprehension that creates 2 threading.Thread objects 
threads = [Thread(target=s_process) for x in range(0, 2)] 

# starts thread 1 
# joins thread 1 
# starts thread 2 
# joins thread 2 
for thread in threads: 
    try: 
     thread.start() 
     thread.join() 
    except KeyboardInterrupt: # std Python exception 
     continue # moves to next thread iterable 

編輯：try/except 0 Inlcuded，並用通用的Ctrl + X + C進行測試。