GIL解释器锁

#计算秘密集型， 用多进程
from multiprocessing import Process
from threading import Thread
import os, time
def task():
    res = 0
    for i in range(10000000):
        res*=i
if __name__ == '__main__':
    li = list()
    print(os.cpu_count())  #  打印计算机是多少核
    start = time.time()
    for i in range(4):
        #p = Process(target=task)  #耗时1.46多秒
        p = Thread(target=task)  # 耗时2.14多秒
        li.append(p)
        p.start()
    for p in li:
        p.join()
    stop = time.time()
    print(stop - start)

# io密集型用多线程
from multiprocessing import Process
from threading import Thread
import os, time
def task():
    time.sleep(2)
if __name__ == '__main__':
    li = list()
    print(os.cpu_count())
    start = time.time()
    for i in range(4):
        p = Process(target=task)  #创造进程用2.17多秒
        #p = Thread(target=task)  #创造线程用2.00多秒
        li.append(p)
        p.start()
    for p in li:
        p.join()
    stop = time.time()
    print(stop - start)



'''io型就用多线程， 计算型就用多进程'''