信号量，停车位限定数目锁

# project:pybuilder 
# author:slx
# datetime:2019/2/20 1:23
# software: PyCharm

import time
import threading

class Mythread(threading.Thread):
    # def __init__(self):
    #     super(Mythread,self).__init__()
    def run(self):
        if semaphore.acquire():
            print(self.name)
            time.sleep(3)
            semaphore.release()
if __name__ == '__main__':
    semaphore = threading.BoundedSemaphore(3)
    thrs=[]
    for i in range(23):
        thrs.append(Mythread())
    for t in thrs:
        t.start()