python使用Scrapy框架抓取起点中文网免费小说案例

使用工具,ubuntu,python,pycharm
1、使用pycharm建立项目：过程略
2、安装scrapy框架

pip install Scrapy

3、建立scrapy项目：

1.建立爬虫项目

scrapy startproject qidian

2.建立爬虫，先进入爬虫项目目录

cd qidian/
scrapy genspider book book.qidian.com

建立完成后项目目录以下

目录下的的book.py就是咱们的爬虫文件

4、打开book.py编写爬虫的代码

1.进入须要爬去的书的目录，找到开始url
设置start_url:

#鬼吹灯图书目录
start_urls = ['https://book.qidian.com/info/53269#Catalog']

二、在建立项目的时候，筛选的url地址为：

allowed_domains = ['book.qidian.com']

打开图书章节后发现章节的url以下：
 # https://read.qidian.com/chapter/PNjTiyCikMo1/FzxWdm35gIE1
  因此须要将read.qidian.com 加入allowed_domains 中，

allowed_domains = ['book.qidian.com', 'read.qidian.com']

剩下的就是经过xpath 获取抓取到的内容，提取咱们须要的内容
完整代码以下

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

logger = logging.getLogger(__name__)


class BookSpider(scrapy.Spider):
    name = 'book'
    allowed_domains = ['book.qidian.com', 'read.qidian.com']
    start_urls = ['https://book.qidian.com/info/53269#Catalog']

    def parse(self, response):
        # 获取章节列表
        li_list = response.xpath('//div[@class="volume"][2]/ul/li')
        # 列表循环取出章节名称和章节对应的url
        for li in li_list:
            item = {}
            # 章节名称
            item['chapter_name'] = li.xpath('./a/text()').extract_first()
            # 章节url
            item['chapter_url'] = li.xpath('./a/@href').extract_first()
            # 获取到的url //read.qidian.com/chapter/PNjTiyCikMo1/TpiSLsyH5Hc1
            # 须要从新构造
            item['chapter_url'] = 'https:' + item['chapter_url']
            # 循环抓取每一个章节的内容
            if item['chapter_url'] is not None:
                # meta：传递item数据
                yield scrapy.Request(item['chapter_url'], callback=self.parse_chapter, meta={'item': item})

    def parse_chapter(self, response):
        item = response.meta['item']
        # 获取文章内容
        item['chapter_content'] = response.xpath('//div[@class="read-content j_readContent"]/p/text()').extract()
        yield item

5、将爬去数据保存到mongodb中

1.修改setting文件
找到并打开注释：

ITEM_PIPELINES = {
    'qidain.pipelines.QidainPipeline': 300,
}

2.添加monggodb相关配置

# 主机地址
MONGODB_HOST = '127.0.0.1'
# 端口
MONGODB_PORT = 27017
# 须要保存的数据哭名字
MONGODB_DBNAME = 'qidian'
# 保存的文件名
MONGODB_DOCNAME = 'dmbj'

3.在pipelines.py文件中保存数据，最终文件内容以下

# -*- 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

from scrapy.conf import settings
import pymongo


class QidainPipeline(object):
    def __init__(self):
        '''在__init__中配置mongodb'''
        host = settings['MONGODB_HOST']
        port = settings['MONGODB_PORT']
        db_name = settings['MONGODB_DBNAME']
        client = pymongo.MongoClient(host=host, port=port)
        db = client[db_name]
        self.post = db[settings['MONGODB_DOCNAME']]

    def process_item(self, item, spider):
        self.post.insert(item)
        return item