介绍

本篇涉及的内容主要是获取分类下的所有图书数据，并写入MySQL

准备

Python3.6、Scrapy、Twisted、MySQLdb等

演示

代码

一、创建项目

scrapy startproject BookSpider #创建项目

scrapy genspider douban book.douban.com #创建豆瓣爬虫

二、创建测试类(main.py)

from scrapy.cmdline import execute

execute(['scrapy', 'crawl', 'douban'])

三、修改配置(spiders/settings.py)

USER_AGENT = 'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/76.0.3809.100 Safari/537.36' #浏览器

ROBOTSTXT_OBEY = False #不遵循豆瓣网站的爬虫协议

四、设置爬取的分类(spiders/douban.py)

start_urls = ['https://book.douban.com/tag/神经网络'] # 只测试爬取神经网络

五、获取分类列表页图书数据

from scrapy.http import Request

from urllib.parse import urljoin

def parse(self, response):

get_nodes = response.xpath('//div[@id="subject_list"]/ul/li/div[@class="pic"]/a')

for node in get_nodes:

url = node.xpath("@href").get()

img_url = node.xpath('img/@src').get()

yield Request(url=url, meta={"img_url": img_url}, callback=self.parse_book) # 传递img_url值 放在meta里面， parse_book回调函数，获取的详情再分析

next_url = response.xpath('//div[@class="paginator"]/span[@class="next"]/a/@href').get() # 获取下一页地址

if(next_url):

yield Request(url=urljoin(response.url, next_url), callback=self.parse) # 获取下一页内容

六、定义数据模型(spiders/items.py)

class BookspiderItem(scrapy.Item):

# define the fields for your item here like:

# name = scrapy.Field()

name = scrapy.Field()

author = scrapy.Field()

publish = scrapy.Field()

page_num = scrapy.Field()

isbm = scrapy.Field()

binding = scrapy.Field()

publish_date = scrapy.Field()

price = scrapy.Field()

rate = scrapy.Field()

img_url = scrapy.Field()

image_path = scrapy.Field()

七、获取图书详情数据

import re

from BookSpider.items import BookspiderItem

def parse_book(self, response):

BookItem = BookspiderItem()

BookItem['name'] = response.xpath('//span[@property="v:itemreviewed"]/text()').get("").strip()

BookItem['author'] = response.xpath('//span[contains(text(), "作者")]/following-sibling::a[1]/text()').get("").split()[-1]

BookItem['publish'] = response.xpath('//span[contains(text(), "出版社")]/following-sibling::text()').get("").strip()

page_num = response.xpath('//span[contains(text(), "页数")]/following-sibling::text()').get("").strip()

BookItem['page_num'] = 0 if(page_num == '') else page_num

BookItem['isbm'] = response.xpath('//span[contains(text(), "ISBN")]/following-sibling::text()').get("").strip()

BookItem['binding'] = response.xpath('//span[contains(text(), "装帧")]/following-sibling::text()').get("").strip()

BookItem['publish_date'] = response.xpath('//span[contains(text(), "出版年")]/following-sibling::text()').get("").strip()

price = response.xpath('//span[contains(text(), "定价")]/following-sibling::text()').get("").strip()

BookItem['price'] = '' if(len(price) == 0) else re.findall(r'\d+\.?\d*', price)[0]

BookItem['rate'] = response.xpath('//div[contains(@class, "rating_self ")]/strong/text()').get("").strip()

BookItem['img_url'] = [response.meta.get('img_url')] #图片是列表

yield BookItem

八、下载图片

1、创建images文件加

2、配置spiders/settings.py

ITEM_PIPELINES = {

'BookSpider.pipelines.ImageStorePipeline': 1, #后面的数据是优先级

}

IMAGES_URLS_FIELD = "image_url"

IMAGES_STORE = os.path.join(os.path.abspath(os.path.dirname(__file__)), 'images')

3、创建ImageStorePipeline类(spiders/pipelines.py)

from scrapy.pipelines.images import ImagesPipeline

from scrapy.exceptions import DropItem

from scrapy.http import Request

class ImageStorePipeline(ImagesPipeline):

default_headers = {

'accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3',

'accept-encoding': 'gzip, deflate, br',

'accept-language': 'zh-CN,zh;q=0.9',

'user-agent': 'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/76.0.3809.100 Safari/537.36', #这个一定要

}

def get_media_requests(self, item, info):

for image_url in item['img_url']:

self.default_headers['referer'] = image_url

yield Request(image_url, headers=self.default_headers)

def item_completed(self, results, item, info):

image_path = [x['path'] for ok, x in results if ok]

if not image_path:

raise DropItem("Item contains no images")

item['image_path'] = image_path

return item

八、写入数据库

1、配置spiders/settings.py

#设置数据库

MYSQL_HOST = ""

MYSQL_DBNAME = ""

MYSQL_USER = ""

MYSQL_PASSWORD = ""

ITEM_PIPELINES = {

'BookSpider.pipelines.ImageStorePipeline': 1,

'BookSpider.pipelines.MysqlTwistedPipeline': 30,

}

2、创建MysqlTwistedPipeline类(spiders/pipelines.py)

import MySQLdb.cursors

from twisted.enterprise import adbapi

class MysqlTwistedPipeline(object):

def __init__(self, dbpool):

self.dbpool = dbpool

@classmethod #静态方法，会优先执行from_settings， 这样self.dbpool就有值了

def from_settings(cls, settings):

dbpool = adbapi.ConnectionPool("MySQLdb", host=settings['MYSQL_HOST'], db = settings['MYSQL_DBNAME'], user = settings['MYSQL_USER'], passwd = settings['MYSQL_PASSWORD'], charset = 'utf8', cursorclass = MySQLdb.cursors.DictCursor, use_unicode = True)

return cls(dbpool)

def process_item(self, item, spider):

query = self.dbpool.runInteraction(self.do_insert, item)

query.addErrback(self.handle_error,item,spider)

def do_insert(self, cursor, item):

insert_sql = """

insert into douban(name, author, publish, page_num, isbm, binding, publish_date, price, rate, img_url, image_path)

values (%s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s)

"""

cursor.execute(insert_sql, (item['name'], item['author'], item['publish'], item['page_num'], item['isbm'], item['binding'], item['publish_date'], item['price'], item['rate'], item['img_url'], item['image_path']))

def handle_error(self, failure, item, spider):

print(failure)

九、测试

1、执行main.py文件