优雅的爬虫

Python Web 爬取

Thomas Laetsch

Data Scientist, NYU

您的爬虫

import scrapy
from scrapy.crawler import CrawlerProcess

class SpiderClassName(scrapy.Spider):
    name = "spider_name"
    # the code for your spider
    ...

process = CrawlerProcess()

process.crawl(SpiderClassName)

process.start()

您的爬虫

必需的导入

import scrapy
from scrapy.crawler import CrawlerProcess

我们将关注：实际的爬虫

class SpiderClassName(scrapy.Spider):
    name = "spider_name"
    # the code for your spider
    ...

运行爬虫

# initiate a CrawlerProcess
process = CrawlerProcess()

# tell the process which spider to use
process.crawl(YourSpider)

# start the crawling process
process.start()

织网

class DCspider( scrapy.Spider ):

    name = 'dc_spider'

    def start_requests( self ):
        urls = [ 'https://www.datacamp.com/courses/all' ]
        for url in urls:
            yield scrapy.Request( url = url, callback = self.parse )

    def parse( self, response ):
        # simple example: write out the html
        html_file = 'DC_courses.html'
        with open( html_file, 'wb' ) as fout:
            fout.write( response.body )

需要一个名为 start_requests 的函数
至少需要一个解析函数来处理 HTML 代码

一起织网

Python Web 爬取