"""
线程池(thread pool)
"""
from concurrent.futures import ThreadPoolExecutor
import timedef task(name):print(f"路人{name}号")time.sleep(1)return name + 10if __name__ == '__main__':# 创建线程池pool = ThreadPoolExecutor(5) # 线程池中的"线程数"10个,永远是这十个线程,只是内容和对象变了# 往线程池中提交任务---"创建线程"(并非真正独立再建立一个新的线程)f_list = []for i in range(1, 31):future = pool.submit(task, i) # 往线程池中提交任务,返回一个对象f_list.append(future) # 把对象(地址)存起来pool.shutdown() # 关闭线程池,等待线程池中所有任务运行完毕for i in f_list: # 遍历对象# 获得对象的result方法的值,若此result方法没有结果,则阻塞此处,等待它所对应的线程的运行结果print("任务结果:", i.result())
进程池
"""
进程池(process pool)
"""
from concurrent.futures import ProcessPoolExecutor
import os
import timedef task(name):print(f"对象{name}号-----{os.getpid()}")time.sleep(3)return name + 10if __name__ == '__main__':# 创建进程池pool = ProcessPoolExecutor(3) # 一但进程池中进程的数量定下来后,永远都是这些进程在运作# 运行30个进程,3个为一批,一批运行完后,再运行下一批,共运行10批。进程都是同样的那3个f_list = []for i in range(30):future = pool.submit(task, i) # 往进程池中提交任务,返回一个对象,f_list.append(future) # 把对象(地址)存起来for i in f_list: # 遍历对象# 获得对象的result方法的值,若此result方法没有结果,则阻塞此处,等待它所对应的进程的运行结果print("任务结果:", i.result())
回调机制
"""
回调机制
"""
from concurrent.futures import ProcessPoolExecutor
import time
import osdef task(name):print(f"进程{name}号 ---> 进程号>>>{os.getpid()}")time.sleep(3)return name + 10def call_back(obj):print("返回的结果>>>", obj.result())if __name__ == '__main__':# 创建进程池pool = ProcessPoolExecutor(3)# 发送任务for i in range(1, 31):# 异步回调机制future = pool.submit(task, i).add_done_callback(call_back)
yield 进阶
# # 当函数有yield的时候,它已经是生成器函数了
# def f1():
# yield "hello"
# yield "world"
#
#
# g = f1() # 调用生成器函数不会执行函数体内容,它会得到一个可迭代的生成器对象
# print(next(g))
# print(next(g))
#
# for i in f1():
# print(i)
#
#
# def f2():
# return [i for i in range(100)]
#
#
# def f3():
# for i in range(100):
# yield i
#
#
# res = f3()
#
#
# def f4():
# res = yield "hello"
# yield res
#
#
# g = f4()
# print(next(g))
# print(g.send("world"))# # yield from语句
# def f5():
# for s in "abc":
# yield s
# for i in range(3):
# yield i
#
#
# for i in f5():
# print(i)
#
#
# def f6():
# yield from "abc"
# yield from range(3)
#
#
# for i in f6():
# print(i)def sub():yield "a"yield "b"return "c"def link():res = yield from sub()print("结果>>>", res)g = link()
next(g)
next(g)
next(g)
协程
"""
协程:
也可以称为微线程,它是一种用户态内的上下文切换技术,简单说就是在单线程下实现并发效果
"""
import time"""
进程:资源单位
线程:执行单位
协程:程序员人为创造出来的,不存在(切换+保存)当程序遇到IO的时候,通过我们写的代码,让我们的代码自动完成切换
也就是我们通过代码来监听IO,一旦程序遇到IO,就在代码层面上自动切换,
给cpu的感觉是"咋回事,你这个程序没有IO操作?咋不让我歇会啊!!!""""# # 单线程下执行技术密集型
# # 串行计数:0.44606804847717285
# # 切换计数:0.7273049354553223
# def f1():
# n =0
# for i inrange(10000000):
# n +=1
# yield
#
#
# def f2():
# g =f1()
# n =0
# for i inrange(10000000):
# n +=1
# next(g)
#
#
# start = time.time()
# f2()
# end = time.time()
# print(end - start)# 单线程下执行IO密集型
from gevent import monkeymonkey.patch_all()
from gevent import spawn # spawn 有一定的问题,需要加上猴子补丁def da():for _ inrange(3):print("哒")time.sleep(0.5)def mie():for _ inrange(3):print("咩")time.sleep(2)def buyao():for _ inrange(3):print("不要")time.sleep(5)start = time.time()
g1 =spawn(da) # 异步提交任务---执行并监听da()函数,有IO操作就跳到其他代码运行
g2 =spawn(mie)
g3 =spawn(buyao)
g1.join()
g2.join()
g3.join()end = time.time()print(end - start) # 12.0030574798583986.050061464309692