Python爬虫框架scrapy实现的文件下载功能示例

# -*- coding: utf-8 -*-import scrapyfrom scrapy.linkextractor import LinkExtractorfrom weidashang.items import matplotlibclass MatSpider(scrapy.Spider):  name = "mat"  allowed_domains = ["matplotlib.org"]  start_urls = ['https://matplotlib.org/examples']  def parse(self, response):　　　　　　　#抓取每个脚本文件的访问页面，拿到后下载    link = LinkExtractor(restrict_css='div.toctree-wrapper.compound li.toctree-l2')    for link in link.extract_links(response):      yield scrapy.Request(url=link.url,callback=self.example)  def example(self,response):　　　　　　#进入每个脚本的页面，抓取源码文件按钮，并和base_url结合起来形成一个完整的url    href = response.css('a.reference.external::attr(href)').extract_first()    url = response.urljoin(href)    example = matplotlib()    example['file_urls'] = [url]    return example

class MyFilePlipeline(FilesPipeline):  def file_path(self, request, response=None, info=None):    path = urlparse(request.url).path    return join(basename(dirname(path)),basename(path))

ITEM_PIPELINES = {  'weidashang.pipelines.MyFilePlipeline': 1,}FILES_STORE = 'examples_src'

class matplotlib(Item):  file_urls = Field()  files = Field()

from scrapy.cmdline import executeexecute(['scrapy', 'crawl', 'mat','-o','example.json'])