1.引言
爬取摄图网插画栏目中各个类目下的全部图片。
要求：将所有爬取的图片保存至以各自所属类别命名的文件夹中。
2.流程分析
首先这个任务属于一个两层网络爬虫，因为实际图片的下载路径位于第二层，所以我们必须从第一层网页中获取第二层网页的URL，接着从第二层网页中抓取各个图片的下载地址。
在这里插入图片描述
上图展示的网页是我们初始请求的网页，其中每个图片对应一个插画类目，共100多个类目；我们需要请求该网页，并抓取每个插画类目对应的URL。
在这里插入图片描述
由上图CSS选择器定位情况，我们知道一共有120个插画类目，每一个类目都存储在<div class="pl-list>标签中；相应的，每个类目的URL也存储在其中。
在这里插入图片描述
进入到其中的开学季插画类目，利用CSS选择器定位到每张图片的下载地址，我们发现一共有100张图片。
根据以上的分析，我们的目标是爬取并下载120个插画类目下共12000张图片。
3.代码实现
- 新建项目
在终端分别输入以下命令行，新建爬虫项目。
scrapy startproject shetuwang
cd shetu
scrapy genspider picture 699pic.com
- 编写items.py源文件，设定需要爬取的字段
# Define here the models for your scraped items
#
# See documentation in:
# https://docs.scrapy.org/en/latest/topics/items.html
import scrapy
class ShetuwangItem(scrapy.Item):
title = scrapy.Field() #图片所属类别
imgurls = scrapy.Field() #图片下载地址
images = scrapy.Field() #图片信息
# define the fields for your item here like:
# name = scrapy.Field()
#pass
- 编写picture.py源文件，制定爬虫的数据爬取工作
import scrapy
from scrapy import Request
from ..items import ShetuwangItem
class PictureSpider(scrapy.Spider):
name = 'picture'
allowed_domains = ['699pic.com']
start_urls = ['http://699pic.com/chahua/']
def parse(self, response):
typeurls = response.css(".pl-list a::attr(href)").extract()
for imgurl in typeurls:
imgurl = 'https:'+imgurl
yield Request(imgurl,callback=self.parse_image)
def parse_image(self,response):
item = ShetuwangItem()
imageurls = response.css("div.list a img::attr(data-original)").extract()
if imageurls:
title = response.css("strong.Gjc::text").extract()[0]
item['title'] = title
imgurls = []
for imageurl in imageurls:
imageurl = 'https:' + imageurl
imgurls.append(imageurl)
item['imgurls'] = imgurls
yield item
- 编写pipelines.py源文件，处理图片的下载与保存工作
# 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
from scrapy.pipelines.images import ImagesPipeline
from scrapy import Request
class ShetuwangPipeline:
def process_item(self, item, spider):
return item
class DownloadImagesPipeline(ImagesPipeline):
def get_media_requests(self,item,info):
for imgurl in item['imgurls']:
yield Request(imgurl,meta={'title':item['title']})
def file_path(self,request,response=None,info=None):
title = request.meta['title']
imgname = request.url.split('/')[-1]
filename = u'{0}/{1}'.format(title,imgname)
return filename
def thumb_path(self,request,thumb_id,response=None,info=None):
title = request.meta["title"]
image_name = request.url.split("/")[-1]
thumbname = u'{0}/{1}/{2}'.format(title,thumb_id,image_name)
return thumbname
- 编写settings.py源文件，配置爬虫项目
# Scrapy settings for shetuwang 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 = 'shetuwang'
SPIDER_MODULES = ['shetuwang.spiders']
NEWSPIDER_MODULE = 'shetuwang.spiders'
# Crawl responsibly by identifying yourself (and your website) on the user-agent
#USER_AGENT = 'shetuwang (+http://www.yourdomain.com)'
# Obey robots.txt rules
ROBOTSTXT_OBEY = False
# 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',
'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/92.0.4515.131 Safari/537.36 Edg/92.0.902.67',
}
# Enable or disable spider middlewares
# See https://docs.scrapy.org/en/latest/topics/spider-middleware.html
#SPIDER_MIDDLEWARES = {
# 'shetuwang.middlewares.ShetuwangSpiderMiddleware': 543,
#}
# Enable or disable downloader middlewares
# See https://docs.scrapy.org/en/latest/topics/downloader-middleware.html
#DOWNLOADER_MIDDLEWARES = {
# 'shetuwang.middlewares.ShetuwangDownloaderMiddleware': 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 = {
#'shetuwang.pipelines.ShetuwangPipeline': 300,
'shetuwang.pipelines.DownloadImagesPipeline': 300,
}
IMAGES_STORE = 'D:\\scrapy\\shetuwang'
IMAGES_URLS_FIELD = 'image_urls'
IMAGES_RESULT_FIELD = 'images'
IMAGES_THUMBS = {'small':(80,80),'big':(300,300)}
# 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'
- 在终端用命令行运行爬虫，进行爬取
scrapy crawl picture
- 查看运行结果
在没有分布式爬取技术加持的情况下，12000张图片爬取下来需要较长时间，这里只展示爬取到的部分图片。
在这里插入图片描述
此刻只爬取完了两个类目，分别是开学季插画、微光渐变插画。
开学季
以上为开学季插画，还包含两个不同尺寸的缩略图。
微光渐变
以上为微光渐变插画，及不同尺寸的缩略图。
3.更深入
通过查看下载的图片，我发现每张图片上都有水印；需要有摄图网账号，且注册会员才能下载无水印图片。
如果我已经满足了下载无水印图片的资质了，该如何改进这个项目，进行无水印图片的爬取呢？
欢迎大家来评论区交流意见！
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