爬虫_scrapy_当当网爬取数据
作者：互联网
1.创建项目
scrapy startproject scrapy_dangdang
2.创建一个爬虫文件
爬取地址：http://category.dangdang.com/cp01.01.02.00.00.00.html
scrapy genspider dang http://category.dangdang.com/cp01.01.02.00.00.00.html
3.各部分代码
dang.py文件
import scrapy
from scrapy_dangdang.items import ScrapyDangdangItem
class DangSpider(scrapy.Spider):
name = 'dang'
# 多页请求一般情况下只写域名
allowed_domains = ['category.dangdang.com']
start_urls = ['http://category.dangdang.com/cp01.01.02.00.00.00.html']
base_url='http://category.dangdang.com/pg'
page = 1
def parse(self, response):
# pipelines 下载数据
# items 定义数据结构的
# src='//ul[@id="component_59"]/li//img/@src'
# alt='//ul[@id="component_59"]/li//img/@alt'
# price='//ul[@id="component_59"]/li//p[@class="price"]/span[1]/text()'
# 所有的selector的对象都可以再次调用xpath方法
li_list = response.xpath('//ul[@id="component_59"]/li')
print('=====================获取数据================================')
for li in li_list:
# 这里涉及到了图片的懒加载
src = li.xpath('.//img/@data-original').extract_first()
# 第一张图片和其他图片的标签的熟悉是不一样的
# 第一张图片的src是可以使用的，其他的图片的地址是data-original
if src:
src = src
else:
src = li.xpath('.//img/@src').extract_first()
name = li.xpath('.//img/@alt').extract_first()
price = li.xpath('.//p[@class="price"]/span[1]/text()').extract_first()
book = ScrapyDangdangItem(src=src,name=name,price=price)
# 获取一个book就将book交给pipelines
yield book
#每一页爬取的业务逻辑都是一样的，所以我们只需要将执行的那个页的请求再次调用parse方法就可以了
if self.page < 10:
self.page = self.page + 1
url = self.base_url+str(self.page)+'-cp01.01.02.00.00.00.html'
# 调用parse方法
# scrapy.Request就是scrapy的get请求
yield scrapy.Request(url=url,callback=self.parse)
items.py文件
# Define here the models for your scraped items
#
# See documentation in:
# https://docs.scrapy.org/en/latest/topics/items.html
import scrapy
class ScrapyDangdangItem(scrapy.Item):
# define the fields for your item here like:
# name = scrapy.Field()
# 通俗的说就是你要下载的数据都有什么
# 图片
src = scrapy.Field()
# 名字
name = scrapy.Field()
# 价格
price = scrapy.Field()
pass
pipelines.py文件
# 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
# useful for handling different item types with a single interface
from itemadapter import ItemAdapter
# 如果想要使用管道的话，那么就必须在settings中开启管道
class ScrapyDangdangPipeline:
# 在爬虫文件开始的之前就执行一个方法
def open_spider(self,spider):
self.fp = open('book.json','w',encoding='utf-8')
# item就是yield后面的book对象
def process_item(self, item, spider):
# 以下这种模式不推荐，因为每传递过来一个对象，那么就打开一次文件，对文件的操作过于频繁
# (1) write方法必须要写一个字符串，而不是其他的对象
# (2)w模式会每一个对象都打开一次文件，覆盖之前的内容，所有用a模式
# with open('book.json','a',encoding='utf-8')as fp:
# fp.write(str(item))
self.fp.write(str(item))
return item
# 在爬虫文件执行完之后，执行的方法
def close_spider(self,spider):
self.fp.close()
import urllib.request
# 多条管道开启
# （1） 定义管道类(下载图片)
# （2）在settings中开启管道
class DangDangDownloadPipeline:
def process_item(self,item,spider):
url = 'http:'+item.get('src')
filename = './books/'+item.get('name')+'.jpg'
urllib.request.urlretrieve(url=url,filename=filename)
return item
settings.py文件
# Scrapy settings for scrapy_dangdang 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.html
BOT_NAME = 'scrapy_dangdang'
SPIDER_MODULES = ['scrapy_dangdang.spiders']
NEWSPIDER_MODULE = 'scrapy_dangdang.spiders'
# Crawl responsibly by identifying yourself (and your website) on the user-agent
#USER_AGENT = 'scrapy_dangdang (+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/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',
# 'Accept-Language': 'en',
#}
# Enable or disable spider middlewares
# See https://docs.scrapy.org/en/latest/topics/spider-middleware.html
#SPIDER_MIDDLEWARES = {
# 'scrapy_dangdang.middlewares.ScrapyDangdangSpiderMiddleware': 543,
#}
# Enable or disable downloader middlewares
# See https://docs.scrapy.org/en/latest/topics/downloader-middleware.html
#DOWNLOADER_MIDDLEWARES = {
# 'scrapy_dangdang.middlewares.ScrapyDangdangDownloaderMiddleware': 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
# 开启管道
ITEM_PIPELINES = {
# 管道可以有很多个，那么管道是有优先级的，优先级的范围是1到1000，值越小优先级越高
'scrapy_dangdang.pipelines.ScrapyDangdangPipeline': 300,
'scrapy_dangdang.pipelines.DangDangDownloadPipeline': 301
}
# 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'
代码地址：https://gitee.com/heating-cloud/python_spider.git
标签：self,当当网,爬取,item,scrapy,html,https,dangdang 来源： https://www.cnblogs.com/ckfuture/p/16327206.html