老师，我们在这里相当于重写了del方法，视频中的p2变量相当于被我们del删除了，p1也是在程序最后一行代码执行完python自动调用del方法把p1删除了，那么我有点奇怪的是，我们重写的这个del方法只有print语句一行，实际上是个假方法，为什么这个假方法我们在调用它删除p2的时候还真的给他删了呢？是不是重写del方法不影响他的删除效果？

你好老师，关于折后价格，我想新建一个类，用组合的方法计算出折后价格再进行比较，写不下去了，蒙了，麻烦你用组合的方法补齐一下我的代码，谢谢

package com.luzhongxu.arrary;

public class Test08 {
    public static void main(String[] args) {
        shangpings x0 = new shangpings(1,"鼠标","BZ",99.21,0.9);
        shangpings x1 = new shangpings(2,"键盘","WO",403.00,0.7);
        shangpings x2 = new shangpings(3,"程序设计","BK",89.00,0.8);
        shangpings x3 = new shangpings(4,"西装","GQ",700.00,0.5);
        shangpings x4 = new shangpings(5,"手机","DM",900.00,0.3);
        shangpings[] x = new shangpings[5];
        x[0] = x0;
        x[1] = x1;
        x[2] = x2;
        x[3] = x3;
        x[4] = x4;
        for(int i = 0;i<x.length;i++){
            System.out.println(x[i]);

        }
    }
}
class shangpings{
     int id;
     String mingcheng;
    String xinghao;
     double price;
     double discount;

    shangpings(){}

    public shangpings(int id, String mingcheng, String xinghao, double price, double discount) {
        this.id = id;
        this.mingcheng = mingcheng;
        this.xinghao = xinghao;
        this.price = price;
        this.discount = discount;
    }

    @Override
    public String toString() {
        return "序号："+getId()+"\t"+"名称："+getMingcheng()+"\t"+"型号："+getXinghao()+"\t"+"价格："+getPrice()+"\t"+"折扣："+getDiscount();
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getMingcheng() {
        return mingcheng;
    }

    public void setMingcheng(String mingcheng) {
        this.mingcheng = mingcheng;
    }

    public String getXinghao() {
        return xinghao;
    }

    public void setXinghao(String xinghao) {
        this.xinghao = xinghao;
    }

    public double getPrice() {
        return price;
    }

    public void setPrice(double price) {
        this.price = price;
    }

    public double getDiscount() {
        return discount;
    }

    public void setDiscount(double discount) {
        this.discount = discount;
    }

}
class zhehou  {   //zhehou= 折后价格
    shangpings sp = new shangpings();
    double zhehou;
    public void zhehou(double price,double discount,double zhehou){
        this.sp.price = price;
        this.sp.discount = discount;
        this.zhehou = zhehou;
        zhehou = price*discount;
        System.out.println(zhehou);

    }
}

老师，我后台也启动了，可是为什么不对呀，

老师，请问，没有明白生成器是什么意思，为什么调用这个函数返回的是一个生成器呢

问题一：老师那我这种情况和上面那个兄弟的问题是一样的，该怎么解决呢？

问题二：这个到底是静态资源被拦截还是路径有问题呢

老师，这段代码没有报错，为什么嵌套循环用不了，是不是定义类表述一个二维数组之后，实际上算是一维数组，不能算二维数组，所以嵌套循环用不了，以下是原码

package com.luzhongxu.arrary;

public class Test08 {
    public static void main(String[] args) {
        shangping[][] x =new shangping[4][];
        shangping x0 = new shangping(1,"鼠标","BZ",99.21,0.9);
        shangping x1 = new shangping(2,"键盘","WO",403.00,0.7);
        shangping x2 = new shangping(3,"程序","BK",89.00,0.8);
        shangping x3 = new shangping(4,"西装","GQ",700.00,0.5);
        shangping x4 = new shangping(5,"手机","DM",900,0.4);

        x[4][0] = x0;
        x[4][1] = x1;
        x[4][2] = x2;
        x[4][3] = x3;
        x[4][4] = x4;

        for(int i =0; i< x.length;i++) {

            for (int j = 0; j <x[i].length; j++) {
                System.out.print(x[i][j]);
            }
            System.out.println();
        }
    }
}
class shangping{
    private int id;
    private String mingcheng;
    private String xinghao;
    private double price;
    private double discount;

    shangping(){}

    public shangping(int id, String mingcheng, String xinghao, double price, double discount) {
        this.id = id;
        this.mingcheng = mingcheng;
        this.xinghao = xinghao;
        this.price = price;
        this.discount = discount;
    }

    @Override
    public String toString() {
        return "序号："+getId()+"\t"+"名称："+getMingcheng()+"\t"+"型号："+getXinghao()+"\t"+"价格："+getPrice()+"\t"+"折扣："+getDiscount();
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getMingcheng() {
        return mingcheng;
    }

    public void setMingcheng(String mingcheng) {
        this.mingcheng = mingcheng;
    }

    public String getXinghao() {
        return xinghao;
    }

    public void setXinghao(String xinghao) {
        this.xinghao = xinghao;
    }

    public double getPrice() {
        return price;
    }

    public void setPrice(double price) {
        this.price = price;
    }

    public double getDiscount() {
        return discount;
    }

    public void setDiscount(double discount) {
        this.discount = discount;
    }
}

老师，你的示范中有一个操作，pycharm中多行代码的同一纵坐标出现一道分割线，然后就可以删除掉多行分割线前的内容，请问你用的快捷键是什么？

老师，如果类装饰器要传函数里面的参数的话怎么传呢？

老师好，控制提示框移动范围时，使用“if else”可以实现，但使用“switch”时没有效果。

应该是我的switch语句没写对（第35行代码），怎么写才正确？求指导，谢谢。

<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>鼠标事件</title>
<style>
    input{
        width: 300px;
        margin: 100px 600px 0px;
    }
    #tips{
        width: 30px;
        height: 25px;
        margin: 0px 750px;
        padding: 0;
        font-size: 18px;
        text-align: center;
        border: 1px solid aqua;
        position: absolute;
        display: none;
    }
</style>
</head>
<body>
    <input type="range" min="0" max="100" value="50">
    <div id="tips"></div>
<script>
    var input=document.querySelector('input');
    var tips=document.getElementById('tips');
    function move(){
        input.onmousemove=function () {
            var x=event.clientX;
            var Y=event.clientY;
            // 使用switch语句控制提示框移动范围????????????????????????????????????????
/*            switch (x) {
                case x<600:tips.style.left=-150+'px';
                    break;
                case x>900:tips.style.left=150+'px';
                    break;
                case x>=600&&x<=900:tips.style.left=(x-750)+'px';
                    break;
            }*/
            // 使用if语句控制提示框移动范围
            if (event.clientX>900){
                x = 900;
            }else if (event.clientX<600){
                x = 600;
            }else{
                tips.style.left=(x-750)+'px';
            }

            tips.innerHTML=input.value;

            // console.log('(x,y):('+x+','+'y'+')');
        }
    };
    input.onmousedown=function () {
        tips.style.display='block'
        move();
    };
    input.onmouseup=function () {
        tips.style.display='none'
        input.onmousemove=null;
    }
</script>
</body>
</html>

老师好，

那个redis16384个插槽实在集群模式下才有的吗？

如果在单机模式下是不是就没有插槽的概念，只有16个库？

老师这是出了什么问题呢，怎么一点击之后就空白页面了。检查不出啥问题了。

<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		
		<style>
			body{
				background-image: url('https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1598617000259&di=b5d1d7f84e70922515532e9c6bc244fb&imgtype=0&src=http%3A%2F%2Fdingyue.ws.126.net%2F2019%2F04%2F19%2Ff76caccfae3e4aafb92d364be54a9ecc.jpeg');
				background-repeat: no-repeat;
				background-size: 1600px 600px;
			}
			
			a{
				font-size: 25px;
				color: white;
			}
		</style>
		
		<script>
			var i=0;
			function changebg(){
				var arr=['https://ss0.bdstatic.com/70cFuHSh_Q1YnxGkpoWK1HF6hhy/it/u=3100633070,1670184186&fm=26&gp=0.jpg','https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1598617671920&di=7aa4cb05c00361f2b49b8b4e0f9fd635&imgtype=0&src=http%3A%2F%2F5b0988e595225.cdn.sohucs.com%2Fq_70%2Cc_zoom%2Cw_640%2Fimages%2F20180613%2F09a3850ee4664b9c931332145bbb0a6f.jpeg','https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1598617736788&di=3db9d05a043556b456d1d2e3fac78f29&imgtype=0&src=http%3A%2F%2Fimgsrc.baidu.com%2Fforum%2Fw%3D580%2Fsign%3D453287f400d162d985ee621421dfa950%2Fb6ecf803918fa0ec4fc0ad3d2c9759ee3d6ddbbc.jpg','https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1598617793589&di=7c942654f5bdedbca95daa62ab6c1155&imgtype=0&src=http%3A%2F%2Fp2.ssl.cdn.btime.com%2Ft01cc72054bb0448dde.jpg%3Fsize%3D608x339','https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1598617841695&di=933b600e0fe543f0c9da939aa914187f&imgtype=0&src=http%3A%2F%2Fimage.uc.cn%2Fs%2Fwemedia%2Fs%2Fupload%2F2018%2F385682cf36990962c0843fe03c174c73.jpg','https://ss0.bdstatic.com/70cFvHSh_Q1YnxGkpoWK1HF6hhy/it/u=1250876743,1234586165&fm=26&gp=0.jpg','https://ss1.bdstatic.com/70cFuXSh_Q1YnxGkpoWK1HF6hhy/it/u=2569621119,693892286&fm=26&gp=0.jpg']
				
				if(i<arr.length-1){
					i++;
				}else{
					i=0;
				}
				
				document.body.style.backgroundImage='url(arr[i])'
			}
		</script>
		
	</head>
	<body>
		
		<a href="javascript:changebg()">点击更换主题</a>
		
	</body>
</html>

老师为什么我登录的时候intelliJ会提示下面的异常？不知道哪里会time out或者为什么会time out呢。。完全没有头绪啊。。

java.net.ConnectException: Operation timed out (Connection timed out)

at java.net.PlainSocketImpl.socketConnect(Native Method) ~[na:1.8.0_211]

at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350) ~[na:1.8.0_211]

at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206) ~[na:1.8.0_211]

at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188) ~[na:1.8.0_211]

at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392) ~[na:1.8.0_211]

at java.net.Socket.connect(Socket.java:589) ~[na:1.8.0_211]

at redis.clients.jedis.Connection.connect(Connection.java:181) ~[jedis-3.1.0.jar:na]

at redis.clients.jedis.BinaryClient.connect(BinaryClient.java:100) ~[jedis-3.1.0.jar:na]

at redis.clients.jedis.BinaryJedis.connect(BinaryJedis.java:1866) ~[jedis-3.1.0.jar:na]

at redis.clients.jedis.JedisFactory.makeObject(JedisFactory.java:117) ~[jedis-3.1.0.jar:na]

at org.apache.commons.pool2.impl.GenericObjectPool.create(GenericObjectPool.java:889) ~[commons-pool2-2.7.0.jar:2.7.0]

at org.apache.commons.pool2.impl.GenericObjectPool.borrowObject(GenericObjectPool.java:424) ~[commons-pool2-2.7.0.jar:2.7.0]

at org.apache.commons.pool2.impl.GenericObjectPool.borrowObject(GenericObjectPool.java:349) ~[commons-pool2-2.7.0.jar:2.7.0]

at redis.clients.jedis.util.Pool.getResource(Pool.java:50) ~[jedis-3.1.0.jar:na]

at redis.clients.jedis.JedisPool.getResource(JedisPool.java:234) ~[jedis-3.1.0.jar:na]

at org.crazycake.shiro.RedisManager.getJedis(RedisManager.java:35) ~[shiro-redis-3.2.3.jar:na]

at org.crazycake.shiro.WorkAloneRedisManager.get(WorkAloneRedisManager.java:50) ~[shiro-redis-3.2.3.jar:na]

at org.crazycake.shiro.RedisSessionDAO.doReadSession(RedisSessionDAO.java:152) ~[shiro-redis-3.2.3.jar:na]

at org.apache.shiro.session.mgt.eis.AbstractSessionDAO.readSession(AbstractSessionDAO.java:168) ~[shiro-core-1.3.2.jar:1.3.2]

at org.apache.shiro.session.mgt.DefaultSessionManager.retrieveSessionFromDataSource(DefaultSessionManager.java:236) ~[shiro-core-1.3.2.jar:1.3.2]

at org.apache.shiro.session.mgt.DefaultSessionManager.retrieveSession(DefaultSessionManager.java:222) ~[shiro-core-1.3.2.jar:1.3.2]

at org.apache.shiro.session.mgt.AbstractValidatingSessionManager.doGetSession(AbstractValidatingSessionManager.java:118) ~[shiro-core-1.3.2.jar:1.3.2]

at org.apache.shiro.session.mgt.AbstractNativeSessionManager.lookupSession(AbstractNativeSessionManager.java:148) ~[shiro-core-1.3.2.jar:1.3.2]

at org.apache.shiro.session.mgt.AbstractNativeSessionManager.getSession(AbstractNativeSessionManager.java:140) ~[shiro-core-1.3.2.jar:1.3.2]

at org.apache.shiro.mgt.SessionsSecurityManager.getSession(SessionsSecurityManager.java:156) ~[shiro-core-1.3.2.jar:1.3.2]

at org.apache.shiro.mgt.DefaultSecurityManager.resolveContextSession(DefaultSecurityManager.java:456) ~[shiro-core-1.3.2.jar:1.3.2]

at org.apache.shiro.mgt.DefaultSecurityManager.resolveSession(DefaultSecurityManager.java:442) ~[shiro-core-1.3.2.jar:1.3.2]

at org.apache.shiro.mgt.DefaultSecurityManager.createSubject(DefaultSecurityManager.java:338) ~[shiro-core-1.3.2.jar:1.3.2]

at org.apache.shiro.subject.Subject$Builder.buildSubject(Subject.java:846) ~[shiro-core-1.3.2.jar:1.3.2]

at org.apache.shiro.web.subject.WebSubject$Builder.buildWebSubject(WebSubject.java:148) ~[shiro-web-1.5.3.jar:1.5.3]

at org.apache.shiro.web.servlet.AbstractShiroFilter.createSubject(AbstractShiroFilter.java:292) ~[shiro-web-1.5.3.jar:1.5.3]

at org.apache.shiro.web.servlet.AbstractShiroFilter.doFilterInternal(AbstractShiroFilter.java:359) ~[shiro-web-1.5.3.jar:1.5.3]

at org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:125) ~[shiro-web-1.5.3.jar:1.5.3]

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.33.jar:9.0.33]

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.33.jar:9.0.33]

at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) ~[spring-web-5.2.5.RELEASE.jar:5.2.5.RELEASE]

at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.5.RELEASE.jar:5.2.5.RELEASE]

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.33.jar:9.0.33]

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.33.jar:9.0.33]

at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) ~[spring-web-5.2.5.RELEASE.jar:5.2.5.RELEASE]

at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.5.RELEASE.jar:5.2.5.RELEASE]

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.33.jar:9.0.33]

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.33.jar:9.0.33]

at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) ~[spring-web-5.2.5.RELEASE.jar:5.2.5.RELEASE]

at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.5.RELEASE.jar:5.2.5.RELEASE]

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.33.jar:9.0.33]

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.33.jar:9.0.33]

at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202) ~[tomcat-embed-core-9.0.33.jar:9.0.33]

at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) [tomcat-embed-core-9.0.33.jar:9.0.33]

at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541) [tomcat-embed-core-9.0.33.jar:9.0.33]

at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139) [tomcat-embed-core-9.0.33.jar:9.0.33]

at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) [tomcat-embed-core-9.0.33.jar:9.0.33]

at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74) [tomcat-embed-core-9.0.33.jar:9.0.33]

at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343) [tomcat-embed-core-9.0.33.jar:9.0.33]

at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:373) [tomcat-embed-core-9.0.33.jar:9.0.33]

at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) [tomcat-embed-core-9.0.33.jar:9.0.33]

at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868) [tomcat-embed-core-9.0.33.jar:9.0.33]

at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1594) [tomcat-embed-core-9.0.33.jar:9.0.33]

at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-9.0.33.jar:9.0.33]

at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [na:1.8.0_211]

at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [na:1.8.0_211]

at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-9.0.33.jar:9.0.33]

at java.lang.Thread.run(Thread.java:748) [na:1.8.0_211]

老师，Mac 版本的网络助手怎么用呢？需要填目标IP和目标端口吗？

运行代码：

from tkinter import *
from PIL import Image, ImageTk
import random


class Application(Frame):

    def __init__(self, master=None):
        super().__init__(master)
        self.master = master
        self.pack()
        self.createWidget()

    def createWidget(self):
        self.btn1 = Button(self, text='送', command=self.song)
        self.btn1.pack()
        self.btnquit = Button(self, text='退出', command=root.destroy, bg='red', fg='blue')
        self.btnquit.pack()

    def get_picture(self, filepath):
        img = Image.open(filepath)
        pic = ImageTk.PhotoImage(img)
        return pic

    def set_picture(self):
        flowers = self.get_picture('flower1.jpg')
        money = self.get_picture('money1.jpg')
        shit = self.get_picture('shit1.jpg')
        book = self.get_picture('book1.jpg')
        phone = self.get_picture('phone1.jpg')
        clothes = self.get_picture('clothes1.jpg')
        song_list = [flowers, money, shit, book, phone, clothes]
        number = random.randint(0, 5)
        return song_list[number]

    def song(self):
        global photo
        photo = self.set_picture()
        self.labpic = Label(self, image=photo)
        self.labpic.pack()


if __name__ == '__main__':
    root = Tk()
    root.geometry('800x600+200+200')
    root.title('首个tk')
    app = Application(master=root)
    root.mainloop()

运行截图：

点击送第二次的时候图片会在第一个图的下面，点击送第三次的时候就看不到图片了

请问能不能每次点击送的时候图片都在正中间？