建设网站软件,无锡网站制作哪家便宜,河南旅游网页设计,wordpress查询页面1. Scrapy install
准备知识
pip 包管理Python 安装XpathCssWindows安装 Scrapy $- pip install scrapy Linux安装 Scrapy $- apt-get install python-scrapy 2. Scrapy 项目创建
在开始爬取之前#xff0c;必须创建一个新的Scrapy项目。进入自定义的项目目录中- pip install scrapy Linux安装 Scrapy $- apt-get install python-scrapy 2. Scrapy 项目创建
在开始爬取之前必须创建一个新的Scrapy项目。进入自定义的项目目录中运行下列命令 $- scrapy startproject mySpider 其中 mySpider 为项目名称可以看到将会创建一个 mySpider 文件夹使用命令查看目录结构 $- tree mySpider 3. Scrapy 自定义爬虫类
通过Scrapy的Spider基础模版顺便建立一个基础的爬虫。也可以不用Scrapy命令建立基础爬虫 $- scrapy genspider gzrbSpider dayoo.com scrapy genspider是一个命令也是scrapy最常用的几个命令之一。至此一个最基本的爬虫项目已经建立完毕了.
文件描述
序列文件名描述1scrapy.cfg是整个Scrapy项目的配置文件2settings.py是上层目录中scrapy.cfg定义的设置文件(决定由谁去处理爬取的内容)3init.pyc是__init__.py的字节码文件4init.py作用就是将它的上级目录变成了一个模块 否则文件夹没有__init__.py不能作为模块导入5items.py是定义爬虫最终需要哪些项 (决定爬取哪些项目)5pipelines.pyScrapy爬虫爬取了网页中的内容后这些内容怎么处理就取决于pipelines.py如何设置 (决定爬取后的内容怎样处理)6gzrbSpider.py自定义爬虫类决定怎么爬
命令描述
序列操作描述1模拟爬广州日报网页scrapy shell https://www.dayoo.com2模拟查看节点数据response.xpath(.//div[classmt35]//ul[classnews-list]).extract() 3运行爬虫scrapy crawl gzrbSpider4. Scrapy 处理逻辑
文件 \spiders\gzrbSpider.py
import scrapy
from mySpider.items import MySpiderItemclass gzrbSpider(scrapy.Spider):name gzrbSpiderallowed_domains [dayoo.com/]start_urls (https://www.dayoo.com,)def parse(self, response):subSelector response.xpath(.//div[classmt35]//ul[classnews-list])items []for sub in subSelector:item MySpiderItem()item[newName] sub.xpath(./li/a/text()).extract()items.append(item)return items文件 Item.py
# Define here the models for your scraped items
#
# See documentation in:
# https://docs.scrapy.org/en/latest/topics/items.htmlimport scrapyclass MySpiderItem(scrapy.Item):# define the fields for your item here like:# name scrapy.Field()newName scrapy.Field()文件 Setting.py
# Scrapy settings for mySpider project
#
# For simplicity, this file contains only settings considered important or
# commonly used. You can find more settings consulting the documentation:
#
# https://docs.scrapy.org/en/latest/topics/settings.html
# https://docs.scrapy.org/en/latest/topics/downloader-middleware.html
# https://docs.scrapy.org/en/latest/topics/spider-middleware.htmlBOT_NAME mySpiderSPIDER_MODULES [mySpider.spiders]
NEWSPIDER_MODULE mySpider.spiders# Crawl responsibly by identifying yourself (and your website) on the user-agent
#USER_AGENT mySpider(http://www.yourdomain.com)# 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://docs.scrapy.org/en/latest/topics/settings.html#download-delay
# See also autothrottle settings and docs
#DOWNLOAD_DELAY 3
# 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 False# Disable Telnet Console (enabled by default)
#TELNETCONSOLE_ENABLED False# Override the default request headers:
#DEFAULT_REQUEST_HEADERS {
# Accept: text/html,application/xhtmlxml,application/xml;q0.9,*/*;q0.8,
# Accept-Language: en,
#}# Enable or disable spider middlewares
# See https://docs.scrapy.org/en/latest/topics/spider-middleware.html
#SPIDER_MIDDLEWARES {
# mySpider.middlewares.mySpiderSpiderMiddleware: 543,
#}# Enable or disable downloader middlewares
# See https://docs.scrapy.org/en/latest/topics/downloader-middleware.html
#DOWNLOADER_MIDDLEWARES {
# mySpider.middlewares.mySpiderDownloaderMiddleware: 543,
#}# Enable or disable extensions
# See https://docs.scrapy.org/en/latest/topics/extensions.html
#EXTENSIONS {
# scrapy.extensions.telnet.TelnetConsole: None,
#}# Configure item pipelines
# See https://docs.scrapy.org/en/latest/topics/item-pipeline.html
ITEM_PIPELINES {mySpider.pipelines.mySpiderPipeline: 300,
}# Enable and configure the AutoThrottle extension (disabled by default)
# See https://docs.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://docs.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文件 pipelines.py
# Define your item pipelines here
#
# Dont forget to add your pipeline to the ITEM_PIPELINES setting
# See: https://docs.scrapy.org/en/latest/topics/item-pipeline.html# useful for handling different item types with a single interface
from itemadapter import ItemAdapter
import time# class mySpiderPipeline:
# def process_item(self, item, spider):
# return itemclass MySpiderPipeline(object):def process_item(self, item, spider):now time.strftime(%Y-%m-%d, time.localtime())fileName gzrb now .txtfor it in item[newName ]:with open(fileName,encodingutf-8,mode a) as fp:# fp.write(item[newName ][0].encode(utf8) \n\n)fp.write(it \n\n)return item
本文代码结果展示 5. Scrapy 扩展
Xpath: Css:
