• 13 并发编程-(线程)-异步调用与回调机制&进程池线程池小练习


    #提交任务的两种方式
    #1、同步调用:提交完任务后,就在原地等待任务执行完毕,拿到结果,再执行下一行代码,导致程序是串行执行

    一、提交任务的两种方式

    1、同步调用:提交任务后,就在原地等待任务完毕,拿到结果,再执行下一行代码,导致程序串行执行

    from concurrent.futures import ThreadPoolExecutor
    import time
    import random
    def produce(name):
        print('%s is producing' %name)
        time.sleep(random.randint(3,5))
        res=random.randint(7,13)*'#'
        return {'name':name,'res':res}
    
    def number(commodity):
        name=commodity['name']
        size=len(commodity['res'])
        print('%s 制造了 《%s》件商品' %(name,size))
    
    
    if __name__ == '__main__':
        pool=ThreadPoolExecutor(13)
    
        p1=pool.submit(produce,'alex').result()  # 取得返回的结果
        number(p1)
    
        p2=pool.submit(produce,'wupeiqi').result()
        number(p2)
    
        p3=pool.submit(produce,'yuanhao').result()
        number(p3)
    
    alex is producing
    alex 制造了 《12》件商品
    wupeiqi is producing
    wupeiqi 制造了 《12》件商品
    yuanhao is producing
    yuanhao 制造了 《11》件商品

    2、回调函数--异步调用:提交完任务后,不用原地等待任务执行完毕,

    from concurrent.futures import ThreadPoolExecutor
    import time
    import random
    def produce(name):
        print('%s is producing' %name)
        time.sleep(random.randint(3,5))
        res=random.randint(7,13)*'#'
        return {'name':name,'res':res}
    
    def number(commodity):
        commodity = commodity.result()
        name=commodity['name']
        size=len(commodity['res'])
        print('%s 制造了 《%s》件商品' %(name,size))
    
    if __name__ == '__main__':
        pool=ThreadPoolExecutor(13)
        pool.submit(produce,'alex').add_done_callback(number)
        pool.submit(produce,'wupeiqi').add_done_callback(number)
        pool.submit(produce,'yuanhao').add_done_callback(number)
    
    alex is producing
    wupeiqi is producing
    yuanhao is producing
    yuanhao 制造了 《9》件商品
    alex 制造了 《8》件商品
    wupeiqi 制造了 《12》件商品
    View Code

    3、进程池线程池小练习

    我们在浏览器上输入一个网址,就能看到一个页面内容,中间经历了那些过程呢:

    浏览器本质套接字客户端,套接字服务端在站点,服务器主机上,把目标文件下载到本机

     3.1 提取网页信息(回调函数)

    # import requests,time
    # requests = requests.get('https://www.cnblogs.com/foremostxl/p/9734442.html')
    # print(requests.text)
    
    from concurrent.futures import ThreadPoolExecutor
    import requests,time
    def get(url):
        request = requests.get(url)
        time.sleep(3)# 模拟网络延迟
        return {'url':url,'content':request.text}
    def parse(res):
        res = res.result()
        print('%s parse res is %s' % (res['url'], len(res['content'])))
    if __name__ == '__main__':
        urls=[
            'http://www.cnblogs.com/foremostxl',
            'https://www.python.org',
            'https://www.baidu.com',
        ]
        pool = ThreadPoolExecutor(3)
        for url in urls:
            pool.submit(get,url).add_done_callback(parse)
    
    http://www.cnblogs.com/foremostxl parse res is 13105
    https://www.baidu.com parse res is 2443
    https://www.python.org parse res is 49097
    View Code

    3.2 基于线程池实现套接字通信

    服务端:

    import socket
    from concurrent.futures import ThreadPoolExecutor
    def Server(ip_port):
        server = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
        server.bind(ip_port)
        server.listen(5)
        while True:
            conn ,addr = server.accept()
            pool.submit(communicate,conn)
        server.close()
    def communicate(conn):
        while True:
            try:
                data = conn.recv(1024)
                conn.send(data.upper())
            except Exception as e:
                print(e)
                break
        conn.close()
    
    if __name__ == '__main__':
        ip_port = ('127.0.0.1',8080)
        pool = ThreadPoolExecutor(2)
        Server(ip_port)
    View Code

    客户端:

    import socket
    client = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
    ip_port = ('127.0.0.1',8080)
    client.connect(ip_port)
    while True:
        msg = input('>>').strip()
        if not msg:break
        client.send(msg.encode('utf-8'))
        data = client.recv(1024)
        print(data.decode('utf-8'))
    client.close()
    View Code
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  • 原文地址:https://www.cnblogs.com/foremostxl/p/9735614.html
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