from threading import Thread

import time

#多线程并发

def func(n):

    time.sleep(1)

    print(n)

for i in range(10):

    Thread(target=func,args=(1,))

    t.start()

class MyTread(Thread):

    def __init__(self,arg):

        super().init()

        self.arg = arg

    def run(self):

        time.sleep(1)

        print(self.arg)

t = MyTread(10)

t.start

import time

from concurrent.futures import ThreadPoolExecutor

def func(n):

    time.sleep(2)

    print(n)

    return n*n

def call_back(m):

    print('结果是 %s'%m.result())

tpool = ThreadPoolExecutor(max_workers=5)   #  默认 不要超过cpu个数*5

for i in  range(20):

    tpool.submit(func,i).add_done_callback(call_back)

# tpool.map(func,range(20))  # 拿不到返回值

# t_lst = []

# for i in  range(20):

#     t = tpool.submit(func,i)

#     t_lst.append(t)

# tpool.shutdown()  # close+join    #

# print('主线程')

# for t in t_lst:print('***',t.result())