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:
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, 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)
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, res):
# 将html转化为etree
etree = self.e_html(res.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, res):
items_data = DoubanItem.get_items(html=res.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。
