软考知识-Python实现PV操作 import threading, time import random s1 = threading.Semaphore(value=1) s2 = threading.Semaphore(value=0) pro = 0 con = 0 cache = 0 product_list = ['小米手机','华为手机','vivo','电脑','手环'] def producer(): global pro,s1,s2,cache count = 4