scrapy 爬取纵横网实战

前言

闲来无事就要练练代码，不知道最近爬取什么网站好，就拿纵横网爬取我最喜欢的雪中悍刀行练手吧

准备

• python3
• scrapy

项目创建：

cmd命令行切换到工作目录创建scrapy项目  两条命令 scarpy startproject与scrapy genspider    然后用pycharm打开项目

D:\pythonwork>scrapy startproject zongheng
New Scrapy project 'zongheng', using template directory 'c:\users\11573\appdata\local\programs\python\python36\lib\site-packages\scrapy\templates\project', created in:
    D:\pythonwork\zongheng

You can start your first spider with:
    cd zongheng
    scrapy genspider example example.com

D:\pythonwork>cd zongheng

D:\pythonwork\zongheng>cd zongheng

D:\pythonwork\zongheng\zongheng>scrapy genspider xuezhong http://book.zongheng.com/chapter/189169/3431546.html
Created spider 'xuezhong' using template 'basic' in module:
  zongheng.spiders.xuezhong

---

确定内容

首先打开网页看下我们需要爬取的内容

其实小说的话结构比较简单 只有三大块  卷 章节 内容

因此 items.py代码：

# -*- coding: utf-8 -*-

# Define here the models for your scraped items
#
# See documentation in:
# https://docs.scrapy.org/en/latest/topics/items.html

import scrapy

class ZonghengItem(scrapy.Item):
    # define the fields for your item here like:
    # name = scrapy.Field()
    book = scrapy.Field()
    section = scrapy.Field()
    content = scrapy.Field()
    pass

---

内容提取spider文件编写

还是我们先创建一个main.py文件方便我们测试代码

from scrapy import cmdline
cmdline.execute('scrapy crawl xuezhong'.split())

然后我们可以在spider文件中先编写

# -*- coding: utf-8 -*-
import scrapy

class XuezhongSpider(scrapy.Spider):
    name = 'xuezhong'
    allowed_domains = ['http://book.zongheng.com/chapter/189169/3431546.html']
    start_urls = ['http://book.zongheng.com/chapter/189169/3431546.html/']

    def parse(self, response):
        print(response.text)
        pass

运行main.py看看有没有输出

发现直接整个网页的内容都可以爬取下来，说明该网页基本没有反爬机制，甚至不用我们去修改user-agent那么就直接开始吧

打开网页 F12查看元素位置 并编写xpath路径 然后编写spider文件

需要注意的是我们要对小说内容进行一定量的数据清洗，因为包含某些html标签我们需要去除

# -*- coding: utf-8 -*-
import scrapy
import re
from zongheng.items import ZonghengItem

class XuezhongSpider(scrapy.Spider):
    name = 'xuezhong'
    allowed_domains = ['book.zongheng.com']
    start_urls = ['http://book.zongheng.com/chapter/189169/3431546.html/']

    def parse(self, response):
        xuezhong_item = ZonghengItem()
        xuezhong_item['book'] = response.xpath('//*[@id="reader_warp"]/div[2]/text()[4]').get()[3:]
        xuezhong_item['section'] = response.xpath('//*[@id="readerFt"]/div/div[2]/div[2]/text()').get()

        content = response.xpath('//*[@id="readerFt"]/div/div[5]').get()
        #content内容需要处理因为会显示<p></p>标签和<div>标签
        content = re.sub(r'</p>', "", content)
        content = re.sub(r'<p>|<div.*>|</div>',"\n",content )

        xuezhong_item['content'] = content
        yield xuezhong_item

        nextlink = response.xpath('//*[@id="readerFt"]/div/div[7]/a[3]/@href').get()
        print(nextlink)
        if nextlink:
            yield scrapy.Request(nextlink,callback=self.parse)

有时候我们会发现无法进入下个链接，那可能是被allowed_domains过滤掉了 我们修改下就可以

唉 突然发现了到第一卷的一百多章后就要VIP了 那我们就先只弄一百多章吧 不过也可以去其他网站爬取免费的 这次我们就先爬取一百多章吧

---

内容保存

接下来就是内容的保存了，这次就直接保存为本地txt文件就行了

首先去settings.py文件里开启  ITEM_PIPELINES

然后编写pipelines.py文件

# -*- coding: utf-8 -*-

# Define your item pipelines here
#
# Don't forget to add your pipeline to the ITEM_PIPELINES setting
# See: https://docs.scrapy.org/en/latest/topics/item-pipeline.html

class ZonghengPipeline(object):
    def process_item(self, item, spider):
        filename = item['book']+item['section']+'.txt'
        with open("../xuezhongtxt/"+filename,'w') as txtf:
            txtf.write(item['content'])
        return item

由于选址失误导致了我们只能爬取免费的一百多章节，尴尬，不过我们可以类比运用到其他网站爬取全文免费的书籍

怎么样 使用scrapy爬取是不是很方便呢