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'''