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threading模块

简单使用

import threading,time'''想要学习Python？Python学习交流群：973783996满足你的需求，资料都已经上传群文件，可以自行下载！'''def coding():    for x in range(3):        print('正在写代码%s'%x)        time.sleep(2)def drawing():    for x in range(3):        print('正在画画%s'%x)        time.sleep(2)def main():    t1 = threading.Thread(target=coding)    t2 = threading.Thread(target=drawing)    t1.start()    t2.start()if __name__ == '__main__':    main()

生产者和消费者

Lock模式的生产者和消费者

import threadingimport random,timegMoney = 1000gLock = threading.Lock()gTotalTimes = 10gTimes = 0class Producer(threading.Thread):    def run(self):        global gMoney        global gTimes        while True:            money = random.randint(100,1000)            gLock.acquire()            #只生产10次，超过就停止，必须把锁给释放掉，否则产生死锁            if gTimes >= gTotalTimes:                gLock.release()                break            gMoney += money            print('%s生产了%d元钱,剩余%d元钱' % (threading.current_thread(), money, gMoney))            #生产一次，次数加1，总共10次            gTimes += 1            gLock.release()            time.sleep(0.5)class Consumer(threading.Thread):    def run(self):        global gMoney        while True:            money = random.randint(100,1000)            gLock.acquire()            if gMoney >= money:                gMoney -= money                print('%s消费了%d元钱,剩余%d元钱' % (threading.current_thread(), money,gMoney))            else:                if gTimes >= gTotalTimes:                    gLock.release()                    break            gLock.release()            time.sleep(0.5)def main():    for x in range(5):        t1 = Producer()        t1.start()    for x in range(2):        t2 = Consumer()        t2.start()if __name__ == '__main__':    main()

下载表情包

网址：http://www.doutula.com/photo/list/?page=1

解析：xpath

不用多线程，速度相对会很慢

import requestsfrom lxml import etreefrom urllib import requestimport osimport re'''想要学习Python？Python学习交流群：973783996满足你的需求，资料都已经上传群文件，可以自行下载！'''def parse_page(url):    headers = {        'User-Agent': 'Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/64.0.3282.140 Safari/537.36',        'Referer': 'https://movie.douban.com/'    }    response = requests.get(url,headers=headers)    text = response.text    html = etree.HTML(text)    imgs = html.xpath("//div[@class='page-content text-center']//img[@class!='gif']")    for img in imgs:        # print(etree.tostring(img))        #图片地址        img_url = img.get('data-original')        #图片名字        alt = img.get('alt')        #替换掉名字里面的特殊字符        alt = re.sub(r'[\?？\.，。！!\*]','',alt)        #获取图片的后缀名（.gif .jpg）        suffix = os.path.splitext(img_url)[1]        #保存的时候完整的图片名字        filename = alt + suffix        request.urlretrieve(img_url,'C:/Users/Administrator/Desktop/images/'+filename)def main():    for x in range(1,10):        url = 'http://www.doutula.com/photo/list/?page=%d'%x        parse_page(url)if __name__ == '__main__':    main()

利用多线程

 main()

• 定义两个队列，和创建多线程
• page_queue()：存放每一页的url
• img_queue()：存放每一页里面所有的表情的url

Producer()

• 从page_queue()队列中去每一页的url，直到队列为空则break
• 用xpath提取出每一页的所有图片的url
• 把每个图片的url和名字存放到img_queue()队列里面

Consumer()

• 从img_queue()队列中取出图片的url和名字
• 下载保存
• 直到page_queue()和img_queue()两个队列都为空则break

代码

import requestsfrom lxml import etreefrom urllib import requestimport osimport reimport threadingfrom queue import Queue'''想要学习Python？Python学习交流群：973783996满足你的需求，资料都已经上传群文件，可以自行下载！'''class Producer(threading.Thread):    headers = {        'User-Agent': 'Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/64.0.3282.140 Safari/537.36',        'Referer': 'https://movie.douban.com/'    }    def __init__(self, page_queue, img_queue, *args, **kwargs):        super(Producer, self).__init__(*args, **kwargs)        self.page_queue = page_queue        self.img_queue = img_queue    def run(self):        while True:            if self.page_queue.empty():                break            url = self.page_queue.get()            self.parse_page(url)    def parse_page(self,url):        response = requests.get(url,headers=self.headers)        text = response.text        html = etree.HTML(text)        imgs = html.xpath("//div[@class='page-content text-center']//img[@class!='gif']")        for img in imgs:            # print(etree.tostring(img))            #图片地址            img_url = img.get('data-original')            #图片名字            alt = img.get('alt')            #替换掉名字里面的特殊字符            alt = re.sub(r'[\?？\.，。！!\*]','',alt)            #获取图片的后缀名（.gif .jpg）            suffix = os.path.splitext(img_url)[1]            #保存的时候完整的图片名字            filename = alt + suffix            self.img_queue.put((img_url,filename))class Consumer(threading.Thread):    def __init__(self,page_queue,img_queue,*args,**kwargs):        super(Consumer, self).__init__(*args,**kwargs)        self.page_queue = page_queue        self.img_queue = img_queue    def run(self):        while True:            if self.img_queue.empty() and self.page_queue.empty():                break            img_url,filename = self.img_queue.get()            request.urlretrieve(img_url, 'C:/Users/Administrator/Desktop/images/' + filename)            print("已下载完一张图片")def main():    page_queue = Queue(1000)    img_queue = Queue(10000)    for x in range(1,1758):        url = 'http://www.doutula.com/photo/list/?page=%d'%x        page_queue.put(url)    for x in range(10):        t = Producer(page_queue,img_queue)        t.start()    for x in range(10):        t = Consumer(page_queue,img_queue)        t.start()if __name__ == '__main__':    main()

结果：

转载地址：http://pinmf.baihongyu.com/