python爬虫框架talonspider简单介绍

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)

具体见qidian_details_by_item.py

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, TextField, 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)

具体见douban_page_by_item.py

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, TextField, 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', 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：

/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。

来源：http://www.jianshu.com/p/c20b7f3d5a78