Python3学习系列（十一）：Scrapy下载文件和图片

前言

可能在大家学习爬虫的过程中已经学会了如何去下载文件和图片的，无非就是传递一个URL地址然后下载即可，那么在Scrapy这个框架中，又是如何下载文件和图片的呢？

在Scrapy中，存在两个处理管道，分别是FilesPipeline，ImagesPipeline，一个用来下载文件，一个用来下载图片，下面用两个实例来说明这两个管道的用法

FilesPipeline

下载下图网站的代码文件

items.py

import scrapy
 
class DownFilesItem(scrapy.Item):
    # define the fields for your item here like:
    # name = scrapy.Field()
    #pass
    #file_urls用来存放要下载的文件url地址
    file_urls = scrapy.Field()
    files = scrapy.Field()

settings.py

BOT_NAME = 'Down_Files'
 
SPIDER_MODULES = ['Down_Files.spiders']
NEWSPIDER_MODULE = 'Down_Files.spiders'
 
# Crawl responsibly by identifying yourself (and your website) on the user-agent
#USER_AGENT = 'Down_Files (+http://www.yourdomain.com)'
 
# Obey robots.txt rules
ROBOTSTXT_OBEY = True
 
ITEM_PIPELINES = {
    #'Down_Files.pipelines.DownFilesPipeline': 300,
    #自动下载文件，本来是FilesPipeline,为了改变下载文件的文件名，重写了FilesPipeline
    #'scrapy.pipelines.files.FilesPipeline':1,
    'Down_Files.pipelines.DownFilesPipeline':1,
}
#下载的文件存放路径
FILES_STORE='Down_Files'

pipelines.py

from scrapy.pipelines.files import FilesPipeline
from urllib.parse import urlparse
from os.path import basename,dirname,join

#改变下载的文件名
class DownFilesPipeline(FilesPipeline):
    #Scrapy源代码用这个方法来命名，return(目录名，文件名),我们改变返回值的目录名和文件名即可
    def file_path(self,request,response=None,info=None):
        path =  urlparse(request.url).path
        return join(basename(dirname(path)),basename(path))

Down_Files.py

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

from scrapy.linkextractors import LinkExtractor
from Down_Files.items import DownFilesItem
 
class DownFileSpider(scrapy.Spider):
    name = 'Down_File'
    allowed_domains = ['matplotlib.org']
    start_urls = ['http://matplotlib.org/examples/index.html']
 
    def parse(self,response):
        le = LinkExtractor(restrict_xpaths=('//*[@id="matplotlib-examples"]/div/ul/li/ul/li/a'),deny='/index.html$')
        for link in le.extract_links(response):
            yield scrapy.Request(link.url,callback=self.parse_files)
 
    def parse_files(self, response):
        href = response.xpath('//div[@class="body"]/div/p/a/@href').extract_first()
        url = response.urljoin(href)
        item = DownFilesItem()
        item['file_urls'] = [url]
        return item

成果图如下

ImagesPipeline

下载So_Image的图片

items.py

import scrapy
 
class DownSoImageItem(scrapy.Item):
    # define the fields for your item here like:
    # name = scrapy.Field()
    #跟下载文件一样，存放图片的url地址
    image_urls = scrapy.Field()

settings.py

BOT_NAME = 'Down_So_Image'
 
SPIDER_MODULES = ['Down_So_Image.spiders']
NEWSPIDER_MODULE = 'Down_So_Image.spiders'
 
# Crawl responsibly by identifying yourself (and your website) on the user-agent
#USER_AGENT = 'Down_So_Image (+http://www.yourdomain.com)'
 
# Obey robots.txt rules
ROBOTSTXT_OBEY = False
 
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 6.1; WOW64) AppleWebKit/537.1 (KHTML, like Gecko) Chrome/22.0.1207.1 Safari/537.1',
}
ITEM_PIPELINES = {
    #'Down_So_Image.pipelines.DownSoImagePipeline': 300,
    'scrapy.pipelines.images.ImagesPipeline':1,
}
 
IMAGES_STORE = 'Down_Images'

Down_Images.py

import scrapy
 
from scrapy.linkextractors import LinkExtractor
from Down_Files.items import DownFilesItem
 
class DownFileSpider(scrapy.Spider):
    name = 'Down_File'
    allowed_domains = ['matplotlib.org']
    start_urls = ['http://matplotlib.org/examples/index.html']
 
    def parse(self,response):
        le = LinkExtractor(restrict_xpaths=('//*[@id="matplotlib-examples"]/div/ul/li/ul/li/a'),deny='/index.html$')
        for link in le.extract_links(response):
            yield scrapy.Request(link.url,callback=self.parse_files)
 
    def parse_files(self, response):
        href = response.xpath('//div[@class="body"]/div/p/a/@href').extract_first()
        url = response.urljoin(href)
        item = DownFilesItem()
        item['file_urls'] = [url]
        return item

成果图片如下