1.为什么写这个?
一些简单的页面,无需用比较大的框架来进行爬取,自己纯手写又比较麻烦
因此针对这个需求写了talonspider:
•1.针对单页面的item提取 - 具体介绍点这里
•2.spider模块 - 具体介绍点这里
2.介绍&&使用
2.1.item
这个模块是可以独立使用的,对于一些请求比较简单的网站(比如只需要get请求),单单只用这个模块就可以快速地编写出你想要的爬虫,比如(以下使用python3,python2见examples目录):
2.1.1.单页面单目标
比如要获取这个网址http://book.qidian.com/info/1004608738 的书籍信息,封面等信息,可直接这样写:
import time from talonspider import Item,TextField,AttrField from pprint import pprint class TestSpider(Item): title = TextField(css_select='.book-info>h1>em') author = TextField(css_select='a.writer') cover = AttrField(css_select='a#bookImg>img',attr='src') def tal_title(self,title): return title def tal_cover(self,cover): return 'http:' + cover if __name__ == '__main__': item_data = TestSpider.get_item(url='http://book.qidian.com/info/1004608738') pprint(item_data)
2.1.1.单页面多目标
比如获取豆瓣250电影首页展示的25部电影,这一个页面有25个目标,可直接这样写:
from talonspider import Item,AttrField from pprint import pprint # 定义继承自item的爬虫类 class DoubanSpider(Item): target_item = TextField(css_select='div.item') title = TextField(css_select='span.title') cover = AttrField(css_select='div.pic>a>img',attr='src') abstract = TextField(css_select='span.inq') def tal_title(self,title): if isinstance(title,str): return title else: return ''.join([i.text.strip().replace('\xa0','') for i in title]) if __name__ == '__main__': items_data = DoubanSpider.get_items(url='https://movie.douban.com/top250') result = [] for item in items_data: result.append({ 'title': item.title,'cover': item.cover,'abstract': item.abstract,}) pprint(result)
2.2.spider
当需要爬取有层次的页面时,比如爬取豆瓣250全部电影,这时候spider部分就派上了用场:
# !/usr/bin/env python from talonspider import Spider,Item,AttrField,Request from talonspider.utils import get_random_user_agent # 定义继承自item的爬虫类 class DoubanItem(Item): target_item = TextField(css_select='div.item') title = TextField(css_select='span.title') cover = AttrField(css_select='div.pic>a>img','') for i in title]) class DoubanSpider(Spider): # 定义起始url,必须 start_urls = ['https://movie.douban.com/top250'] # requests配置 request_config = { 'RETRIES': 3,'DELAY': 0,'TIMEOUT': 20 } # 解析函数 必须有 def parse(self,html): # 将html转化为etree etree = self.e_html(html) # 提取目标值生成新的url pages = [i.get('href') for i in etree.cssselect('.paginator>a')] pages.insert(0,'?start=0&filter=') headers = { "User-Agent": get_random_user_agent() } for page in pages: url = self.start_urls[0] + page yield Request(url,request_config=self.request_config,headers=headers,callback=self.parse_item) def parse_item(self,html): items_data = DoubanItem.get_items(html=html) # result = [] for item in items_data: # result.append({ # 'title': item.title,# 'cover': item.cover,# 'abstract': item.abstract,# }) # 保存 with open('douban250.txt','a+') as f: f.writelines(item.title + '\n') if __name__ == '__main__': DoubanSpider.start()
控制台:
/Users/howie/anaconda3/envs/work3/bin/python /Users/howie/Documents/programming/python/git/talonspider/examples/douban_page_by_spider.py 2017-06-07 23:17:30,346 - talonspider - INFO: talonspider started 2017-06-07 23:17:30,693 - talonspider_requests - INFO: GET a url: https://movie.douban.com/top250 2017-06-07 23:17:31,074 - talonspider_requests - INFO: GET a url: https://movie.douban.com/top250?start=25&filter= 2017-06-07 23:17:31,416 - talonspider_requests - INFO: GET a url: https://movie.douban.com/top250?start=50&filter= 2017-06-07 23:17:31,853 - talonspider_requests - INFO: GET a url: https://movie.douban.com/top250?start=75&filter= 2017-06-07 23:17:32,523 - talonspider_requests - INFO: GET a url: https://movie.douban.com/top250?start=100&filter= 2017-06-07 23:17:33,032 - talonspider_requests - INFO: GET a url: https://movie.douban.com/top250?start=125&filter= 2017-06-07 23:17:33,537 - talonspider_requests - INFO: GET a url: https://movie.douban.com/top250?start=150&filter= 2017-06-07 23:17:33,990 - talonspider_requests - INFO: GET a url: https://movie.douban.com/top250?start=175&filter= 2017-06-07 23:17:34,406 - talonspider_requests - INFO: GET a url: https://movie.douban.com/top250?start=200&filter= 2017-06-07 23:17:34,787 - talonspider_requests - INFO: GET a url: https://movie.douban.com/top250?start=225&filter= 2017-06-07 23:17:34,809 - talonspider - INFO: Time usage:0:00:04.462108 Process finished with exit code 0
此时当前目录会生成douban250.txt,具体见douban_page_by_spider.py。
3.说明
学习之作,待完善的地方还有很多,欢迎提意见,项目地址talonspider。