更新了Scrapy的相关文档

Author: jackfrued

Day66-75/05.解析动态内容.md

@@ -0,0 +1,12 @@
+## 解析动态内容
+
+### JavaScript逆向工程
+
+
+
+### 使用Selenium
+
+
+
+
+

Day66-75/06.表单交互和验证码处理.md

@@ -0,0 +1,34 @@
+## 表单交互和验证码处理
+
+### 提交表单
+
+#### 手动提交
+
+
+
+#### 自动提交
+
+
+
+### 验证码处理
+
+#### 加载验证码
+
+
+
+#### 光学字符识别
+
+光学字符识别（OCR）是从图像中抽取文本的工具，可以应用于公安、电信、物流、金融等诸多行业，例如识别车牌，身份证扫描识别、名片信息提取等。在爬虫开发中，如果遭遇了有文字验证码的表单，就可以利用OCR来进行验证码处理。Tesseract-OCR引擎最初是由惠普公司开发的光学字符识别系统，目前发布在Github上，由Google赞助开发。
+
+![](./res/tesseract.gif)
+
+#### 改善OCR
+
+
+
+#### 处理更复杂的验证码
+
+
+
+#### 验证码处理服务
+

Day66-75/Scrapy的应用01.md

@@ -2,9 +2,9 @@
 
 ### Scrapy概述
 
-Scrapy是Python开发的一个非常流行的网络爬虫框架，可以用来抓取Web站点并从页面中提取结构化的数据，被广泛的用于数据挖掘、数据监测和自动化测试等领域。下图展示了Scrapy的基本架构，其中包含了主要组件和系统的数据处理流程（图中的绿色箭头）。
+Scrapy是Python开发的一个非常流行的网络爬虫框架，可以用来抓取Web站点并从页面中提取结构化的数据，被广泛的用于数据挖掘、数据监测和自动化测试等领域。下图展示了Scrapy的基本架构，其中包含了主要组件和系统的数据处理流程（图中带数字的红色箭头）。
 
-![](./res/scrapy-architecture.jpg)
+![](./res/scrapy-architecture.png)
 
 #### 组件
 
@@ -20,14 +20,22 @@ Scrapy是Python开发的一个非常流行的网络爬虫框架，可以用来
 Scrapy的整个数据处理流程由Scrapy引擎进行控制，通常的运转流程包括以下的步骤：
 
 1. 引擎询问蜘蛛需要处理哪个网站，并让蜘蛛将第一个需要处理的URL交给它。
+
 2. 引擎让调度器将需要处理的URL放在队列中。
+
 3. 引擎从调度那获取接下来进行爬取的页面。
+
 4. 调度将下一个爬取的URL返回给引擎，引擎将它通过下载中间件发送到下载器。
+
 5. 当网页被下载器下载完成以后，响应内容通过下载中间件被发送到引擎；如果下载失败了，引擎会通知调度器记录这个URL，待会再重新下载。
+
 6. 引擎收到下载器的响应并将它通过蜘蛛中间件发送到蜘蛛进行处理。
+
 7. 蜘蛛处理响应并返回爬取到的数据条目，此外还要将需要跟进的新的URL发送给引擎。
+
 8. 引擎将抓取到的数据条目送入条目管道，把新的URL发送给调度器放入队列中。
-9. 上述操作会一直重复直到调度器中没有需要请求的URL，爬虫停止工作。
+
+上述操作中的2-8步会一直重复直到调度器中没有需要请求的URL，爬虫停止工作。
 
 ### 安装和使用Scrapy
 
@@ -45,7 +53,7 @@ $
 (venv) $ tree
 .
 |____ scrapy.cfg
-|____ qianmu
+|____ douban
 | |____ spiders
 | | |____ __init__.py
 | | |____ __pycache__
@@ -68,9 +76,216 @@ $
 根据刚才描述的数据处理流程，基本上需要我们做的有以下几件事情：
 
 1. 在items.py文件中定义字段，这些字段用来保存数据，方便后续的操作。
+
+   ```Python
+   
+   # -*- coding: utf-8 -*-
+   
+   # Define here the models for your scraped items
+   #
+   # See documentation in:
+   # https://doc.scrapy.org/en/latest/topics/items.html
+   
+   import scrapy
+   
+   
+   class DoubanItem(scrapy.Item):
+   
+       name = scrapy.Field()
+       year = scrapy.Field()
+       score = scrapy.Field()
+       director = scrapy.Field()
+       classification = scrapy.Field()
+       actor = scrapy.Field()
+   ```
+
 2. 在spiders文件夹中编写自己的爬虫。
+
+   ```Python
+   
+   # -*- coding: utf-8 -*-
+   import scrapy
+   from scrapy.selector import Selector
+   from scrapy.linkextractors import LinkExtractor
+   from scrapy.spiders import CrawlSpider, Rule
+   
+   from douban.items import DoubanItem
+   
+   
+   class MovieSpider(CrawlSpider):
+       name = 'movie'
+       allowed_domains = ['movie.douban.com']
+       start_urls = ['https://movie.douban.com/top250']
+       rules = (
+           Rule(LinkExtractor(allow=(r'https://movie.douban.com/top250\?start=\d+.*'))),
+           Rule(LinkExtractor(allow=(r'https://movie.douban.com/subject/\d+')), callback='parse_item'),
+       )
+   
+       def parse_item(self, response):
+           sel = Selector(response)
+           item = DoubanItem()
+           item['name']=sel.xpath('//*[@id="content"]/h1/span[1]/text()').extract()
+           item['year']=sel.xpath('//*[@id="content"]/h1/span[2]/text()').re(r'\((\d+)\)')
+           item['score']=sel.xpath('//*[@id="interest_sectl"]/div/p[1]/strong/text()').extract()
+           item['director']=sel.xpath('//*[@id="info"]/span[1]/a/text()').extract()
+           item['classification']= sel.xpath('//span[@property="v:genre"]/text()').extract()
+           item['actor']= sel.xpath('//*[@id="info"]/span[3]/a[1]/text()').extract()
+           return item
+   
+   ```
+
 3. 在pipelines.py中完成对数据进行持久化的操作。
+
+   ```Python
+   
+   # -*- coding: utf-8 -*-
+   
+   # Define your item pipelines here
+   #
+   # Don't forget to add your pipeline to the ITEM_PIPELINES setting
+   # See: https://doc.scrapy.org/en/latest/topics/item-pipeline.html
+   import pymongo
+   
+   from scrapy.exceptions import DropItem
+   from scrapy.conf import settings
+   from scrapy import log
+   
+   
+   class DoubanPipeline(object):
+   
+       def __init__(self):
+           connection = pymongo.MongoClient(settings['MONGODB_SERVER'], settings['MONGODB_PORT'])
+           db = connection[settings['MONGODB_DB']]
+           self.collection = db[settings['MONGODB_COLLECTION']]
+   
+       def process_item(self, item, spider):
+           #Remove invalid data
+           valid = True
+           for data in item:
+             if not data:
+               valid = False
+               raise DropItem("Missing %s of blogpost from %s" %(data, item['url']))
+           if valid:
+           #Insert data into database
+               new_moive=[{
+                   "name":item['name'][0],
+                   "year":item['year'][0],
+                   "score":item['score'],
+                   "director":item['director'],
+                   "classification":item['classification'],
+                   "actor":item['actor']
+               }]
+               self.collection.insert(new_moive)
+               log.msg("Item wrote to MongoDB database %s/%s" %
+               (settings['MONGODB_DB'], settings['MONGODB_COLLECTION']),
+               level=log.DEBUG, spider=spider) 
+           return item
+   
+   ```
+
 4. 修改settings.py文件对项目进行配置。
 
+   ```Python
+   
+   # -*- coding: utf-8 -*-
+   
+   # Scrapy settings for douban project
+   #
+   # For simplicity, this file contains only settings considered important or
+   # commonly used. You can find more settings consulting the documentation:
+   #
+   #     https://doc.scrapy.org/en/latest/topics/settings.html
+   #     https://doc.scrapy.org/en/latest/topics/downloader-middleware.html
+   #     https://doc.scrapy.org/en/latest/topics/spider-middleware.html
+   
+   BOT_NAME = 'douban'
+   
+   SPIDER_MODULES = ['douban.spiders']
+   NEWSPIDER_MODULE = 'douban.spiders'
+   
+   
+   # Crawl responsibly by identifying yourself (and your website) on the user-agent
+   USER_AGENT = 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_8_3) AppleWebKit/536.5 (KHTML, like Gecko) Chrome/19.0.1084.54 Safari/536.5'
+   
+   # Obey robots.txt rules
+   ROBOTSTXT_OBEY = True
+   
+   # Configure maximum concurrent requests performed by Scrapy (default: 16)
+   # CONCURRENT_REQUESTS = 32
+   
+   # Configure a delay for requests for the same website (default: 0)
+   # See https://doc.scrapy.org/en/latest/topics/settings.html#download-delay
+   # See also autothrottle settings and docs
+   DOWNLOAD_DELAY = 3
+   RANDOMIZE_DOWNLOAD_DELAY = True
+   # The download delay setting will honor only one of:
+   # CONCURRENT_REQUESTS_PER_DOMAIN = 16
+   # CONCURRENT_REQUESTS_PER_IP = 16
+   
+   # Disable cookies (enabled by default)
+   COOKIES_ENABLED = True
+   
+   MONGODB_SERVER = '120.77.222.217'
+   MONGODB_PORT = 27017
+   MONGODB_DB = 'douban'
+   MONGODB_COLLECTION = 'movie'
+   
+   # Disable Telnet Console (enabled by default)
+   # TELNETCONSOLE_ENABLED = False
+   
+   # Override the default request headers:
+   # DEFAULT_REQUEST_HEADERS = {
+   #   'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',
+   #   'Accept-Language': 'en',
+   # }
+   
+   # Enable or disable spider middlewares
+   # See https://doc.scrapy.org/en/latest/topics/spider-middleware.html
+   # SPIDER_MIDDLEWARES = {
+   #    'douban.middlewares.DoubanSpiderMiddleware': 543,
+   # }
+   
+   # Enable or disable downloader middlewares
+   # See https://doc.scrapy.org/en/latest/topics/downloader-middleware.html
+   # DOWNLOADER_MIDDLEWARES = {
+   #    'douban.middlewares.DoubanDownloaderMiddleware': 543,
+   # }
+   
+   # Enable or disable extensions
+   # See https://doc.scrapy.org/en/latest/topics/extensions.html
+   # EXTENSIONS = {
+   #    'scrapy.extensions.telnet.TelnetConsole': None,
+   # }
+   
+   # Configure item pipelines
+   # See https://doc.scrapy.org/en/latest/topics/item-pipeline.html
+   ITEM_PIPELINES = {
+       'douban.pipelines.DoubanPipeline': 400,
+   }
+   
+   LOG_LEVEL = 'DEBUG'
+   
+   # Enable and configure the AutoThrottle extension (disabled by default)
+   # See https://doc.scrapy.org/en/latest/topics/autothrottle.html
+   #AUTOTHROTTLE_ENABLED = True
+   # The initial download delay
+   #AUTOTHROTTLE_START_DELAY = 5
+   # The maximum download delay to be set in case of high latencies
+   #AUTOTHROTTLE_MAX_DELAY = 60
+   # The average number of requests Scrapy should be sending in parallel to
+   # each remote server
+   #AUTOTHROTTLE_TARGET_CONCURRENCY = 1.0
+   # Enable showing throttling stats for every response received:
+   #AUTOTHROTTLE_DEBUG = False
+   
+   # Enable and configure HTTP caching (disabled by default)
+   # See https://doc.scrapy.org/en/latest/topics/downloader-middleware.html#httpcache-middleware-settings
+   HTTPCACHE_ENABLED = True
+   HTTPCACHE_EXPIRATION_SECS = 0
+   HTTPCACHE_DIR = 'httpcache'
+   HTTPCACHE_IGNORE_HTTP_CODES = []
+   HTTPCACHE_STORAGE = 'scrapy.extensions.httpcache.FilesystemCacheStorage'
+   ```
 
+