from concurrent.futures import ThreadPoolExecutor
import time
def func(n):
time.sleep(2)
print(n)
return n*n
t_pool = ThreadPoolExecutor(max_workers=20) #max_workers一般不超过CPU*5,创建线程池
t_lst = []
for i in range(20):
t = t_pool.submit(func,i) #提交多线程认为
t_lst.append(t)
t_pool.shutdown() #可以完成close和join的操作
print('主线程')
for t in t_lst:print('****',t.result())
线程池callback
from concurrent.futures import ThreadPoolExecutor
import time
def func(n):
time.sleep(2)
print(n)
return n*n
def call_back(m):
print('结果是%s'%m.result())
t_pool = ThreadPoolExecutor(max_workers=20) #max_workers一般不超过CPU*5,创建线程池
for i in range(20):
t = t_pool.submit(func,i).add_done_callback(call_back)
# t_pool.map(func,range(20)) #t_pool.map是没有返回值的
