Python多线程实现模拟火车站售票

import threading 
from time import sleep, ctime
 
 
N = 100  # 100张票
 
def Sell(name):
     global N
 
     while True:
         if N>0:
            sleep(0.1)  #加入此句，可以让线程卖出第0张票或同一张票
            print("{}卖出第{}张票！\n".format(name,N))
            N=N-1
 
def main():
 
    threads = {}
 
    for i in ( "A" ,"B"  ):
        # 实例化每个 Thread 对象，把函数和参数传递进去，返回 Thread 实例
        t = threading.Thread(target=Sell, args=( i  ,))
        threads[i]=t     # 分配线程
 
    for i in  ("A" ,"B"):
        threads[i].start()    # 开始执行多线程
 
    for i in  ("A" ,"B"):
        threads[i].join()     # 等待线程结束或超时，然后再往下执行
 
    print("程序结束！")
 
 
if __name__ == '__main__':
    main()

import threading
from time import sleep, ctime
 
N = 100  # 100张票
 
lock = threading.Lock()
 
def Sell(name):
 
     global N
 
     while True:
 
         lock.acquire()
         try:
            if N>0:
             sleep(0.1)  #加入此句，可以让线程卖出第0张票或同一张票
             print("{}卖出第{}张票！\n".format(name,N))
             N=N-1
         finally:
             # 改完了一定要释放锁:
             lock.release()
 
def main():
 
    threads = {}
 
    for i in ( "A" ,"B"  ):
        # 实例化每个 Thread 对象，把函数和参数传递进去，返回 Thread 实例
        t = threading.Thread(target=Sell, args=( i  ,))
        threads[i]=t     # 分配线程
 
    for i in  ("A" ,"B"):
        threads[i].start()    # 开始执行多线程
 
    for i in  ("A" ,"B"):
        threads[i].join()     # 等待线程结束或超时，然后再往下执行
 
    print("程序结束！")
 
 
if __name__ == '__main__':
    main()