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：
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import timefrom talonspider import Item, TextField, AttrFieldfrom pprint import pprintclass 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:' + coverif __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：
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from talonspider import Item, TextField, AttrFieldfrom 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：
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# !/usr/bin/env pythonfrom talonspider import Spider, Item, TextField, AttrField, Requestfrom 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', 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])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：
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/Users/howie/anaconda3/envs/work3/bin/python /Users/howie/Documents/programming/python/git/talonspider/examples/douban_page_by_spider.py2017-06-07 23:17:30,346 - talonspider - INFO: talonspider started2017-06-07 23:17:30,693 - talonspider_requests - INFO: GET a url: https://movie.douban.com/top2502017-06-07 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：0:00:04.462108Process 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。
原文链接：http://www.jianshu.com/p/c20b7f3d5a78
