


Recommended Zhonggu Education Python videos (courseware, source code)
《中谷教育Python视频教程》讲的是Python开发的入门教程,它将介绍Python语言的特点和适用范围,Python基本的数据类型,条件判断和循环,函数,以及Python特有的切片和列表生成式。希望本python教程能够让您快速入门并编写简单的Python程序。
课程播放地址:http://www.php.cn/course/501.html
该老师讲课风格:
教师讲课生动形象,机智诙谐,妙语连珠,动人心弦。一个生动形象的比喻,犹如画龙点睛,给学生开启智慧之门;一种恰如其分的幽默,引来学生会心的微笑,如饮一杯甘醇的美酒,给人以回味和留恋;哲人的警句、文化的箴言不时穿插于讲述中间,给人以思考和警醒。
本视频中较为难点是爬虫了:
1、单个网页的简易爬虫
以下爬虫的主要功能是爬取百度贴吧中某一页面的所有图片。代码由主要有两个函数:其中getHtml()通过页面url获取其对应的html内容,getImage()则通过解析html获取图片地址,实现图片的下载。
代码如下:
import urllib import re def getHtml(url): """通过页面url获取其对应的html内容 """ page = urllib.urlopen(url) #打开页面 content = page.read() #读取页面内容 return content def getImage(html): """通过解析html获取图片地址,实现图片的下载 """ regx =r'src="(.+?\.jpg)" pic_ext' #利用正则表达式获得图片url imgreg = re.compile(regx) imglist = re.findall(imgreg,html) x = 0 for imgurl in imglist: filepath ='F:\\Downloads\\'+str(x)+'.jpg' urllib.urlretrieve(imgurl,filepath) #将图片下载到本地 x += 1 print 'completed!' html = getHtml('http://tieba.baidu.com/p/2505265675') imglist = getImage(html)
2、爬取多网页的框架
这里只讲基本思想:第一步是选择一个起始页面,可以直接选择某个网站的主页作为起始页面;第二步是分析这个起始页面的所有链接,然后爬取所有链接的内容;第三步就是无休无止的递归过程,分析爬虫所及的所有子页面内部链接,如果没有爬取过,则继续无休无止的爬取。
借用知乎上谢科兄弟的一段代码来说明。设定初始页面initial_page,爬虫就从这里开始获取页面,url_queue用来存将要爬取的页面队列,seen用来存爬取过的页面。
import Queue initial_page ="http://www.renminribao.com" url_queue =Queue.Queue() seen = set() seen.insert(initial_page) url_queue.put(initial_page) while True: if url_queue.size()>0: current_url = url_queue.get() #取出队例中第一个的url store(current_url) #把这个url代表的网页存储好 for next_url inextract_urls(current_url): #提取把这个url里链向的url if next_url not in seen: seen.put(next_url) url_queue.put(next_url) else: break
这里还给大家推荐了源码资源的下载:http://www.php.cn/xiazai/learn/1944
这个给大家分享了视频的课件
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Maintenance mode is a special operating level entered in Linux systems through single-user mode or rescue mode, and is used for system maintenance and repair. 1. Enter maintenance mode and use the command "sudosystemctlisolaterscue.target". 2. In maintenance mode, you can check and repair the file system and use the command "fsck/dev/sda1". 3. Advanced usage includes resetting the root user password, mounting the file system in read and write mode and editing the password file.

Maintenance mode is used for system maintenance and repair, allowing administrators to work in a simplified environment. 1. System Repair: Repair corrupt file system and boot loader. 2. Password reset: reset the root user password. 3. Package management: Install, update or delete software packages. By modifying the GRUB configuration or entering maintenance mode with specific keys, you can safely exit after performing maintenance tasks.

Linux network configuration can be completed through the following steps: 1. Configure the network interface, use the ip command to temporarily set or edit the configuration file persistence settings. 2. Set up a static IP, suitable for devices that require a fixed IP. 3. Manage the firewall and use the iptables or firewalld tools to control network traffic.

Maintenance mode plays a key role in Linux system management, helping to repair, upgrade and configuration changes. 1. Enter maintenance mode. You can select it through the GRUB menu or use the command "sudosystemctlisolaterscue.target". 2. In maintenance mode, you can perform file system repair and system update operations. 3. Advanced usage includes tasks such as resetting the root password. 4. Common errors such as not being able to enter maintenance mode or mount the file system, can be fixed by checking the GRUB configuration and using the fsck command.

The timing and reasons for using Linux maintenance mode: 1) When the system starts up, 2) When performing major system updates or upgrades, 3) When performing file system maintenance. Maintenance mode provides a safe and controlled environment, ensuring operational safety and efficiency, reducing impact on users, and enhancing system security.

Indispensable commands in Linux include: 1.ls: list directory contents; 2.cd: change working directory; 3.mkdir: create a new directory; 4.rm: delete file or directory; 5.cp: copy file or directory; 6.mv: move or rename file or directory. These commands help users manage files and systems efficiently by interacting with the kernel.

In Linux, file and directory management uses ls, cd, mkdir, rm, cp, mv commands, and permission management uses chmod, chown, and chgrp commands. 1. File and directory management commands such as ls-l list detailed information, mkdir-p recursively create directories. 2. Permission management commands such as chmod755file set file permissions, chownuserfile changes file owner, and chgrpgroupfile changes file group. These commands are based on file system structure and user and group systems, and operate and control through system calls and metadata.

MaintenanceModeinLinuxisaspecialbootenvironmentforcriticalsystemmaintenancetasks.Itallowsadministratorstoperformtaskslikeresettingpasswords,repairingfilesystems,andrecoveringfrombootfailuresinaminimalenvironment.ToenterMaintenanceMode,interrupttheboo


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