Python信号量

import threading
import time

semaphore = threading.Semaphore(3)

def func():
    if semaphore.acquire():   # acquire和release方法同锁的方法，不同在于可以控制多个线程得到该semaphore
        print (threading.currentThread().getName() + ‘ get semaphore‘)
        time.sleep(1)
        semaphore.release()

for i in range(10):
  t1 = threading.Thread(target=func)
  t1.start()