Python爬虫练手,一个简单的Python资讯采集案例

时间:2022-07-22
本文章向大家介绍Python爬虫练手,一个简单的Python资讯采集案例,主要内容包括其使用实例、应用技巧、基本知识点总结和需要注意事项,具有一定的参考价值,需要的朋友可以参考一下。

一个简单的Python资讯采集案例,列表页到详情页,到数据保存,保存为txt文档,网站网页结构算是比较规整,简单清晰明了,资讯新闻内容的采集和保存!

应用到的库

requests,time,re,UserAgent,etree

import requests,time,re
from fake_useragent import UserAgent
from lxml import etree

列表页面

列表页,链接xpath解析

href_list=req.xpath('//ul[@class="news-list"]/li/a/@href')

详情页

内容xpath解析

h2=req.xpath('//div[@class="title-box"]/h2/text()')[0]
author=req.xpath('//div[@class="title-box"]/span[@class="news-from"]/text()')[0]
details=req.xpath('//div[@class="content-l detail"]/p/text()')

内容格式化处理

detail='n'.join(details)

标题格式化处理,替换非法字符

pattern = r"[/\:*?"<>|]"
new_title = re.sub(pattern, "_", title)  # 替换为下划线

保存数据,保存为txt文本

def save(self,h2, author, detail):
    with open(f'{h2}.txt','w',encoding='utf-8') as f:
        f.write('%s%s%s%s%s'%(h2,'n',detail,'n',author))


    print(f"保存{h2}.txt文本成功!")

遍历数据采集,yield处理

def get_tasks(self):
    data_list = self.parse_home_list(self.url)
    for item in data_list:
        yield item

程序运行效果

程序采集效果

附源码参考:

#研招网考研资讯采集
#20200710 by微信:huguo00289
# -*- coding: UTF-8 -*-

import requests,time,re
from fake_useragent import UserAgent
from lxml import etree

class RandomHeaders(object):
    ua=UserAgent()
    @property
    def random_headers(self):
        return {
            'User-Agent': self.ua.random,
        }

class Spider(RandomHeaders):
    def __init__(self,url):
        self.url=url


    def parse_home_list(self,url):
        response=requests.get(url,headers=self.random_headers).content.decode('utf-8')
        req=etree.HTML(response)
        href_list=req.xpath('//ul[@class="news-list"]/li/a/@href')
        print(href_list)
        for href in href_list:
            item = self.parse_detail(f'https://yz.chsi.com.cn{href}')
            yield item


    def parse_detail(self,url):
        print(f">>正在爬取{url}")
        try:
            response = requests.get(url, headers=self.random_headers).content.decode('utf-8')
            time.sleep(2)
        except Exception as e:
            print(e.args)
            self.parse_detail(url)
        else:
            req = etree.HTML(response)
            try:
                h2=req.xpath('//div[@class="title-box"]/h2/text()')[0]
                h2=self.validate_title(h2)
                author=req.xpath('//div[@class="title-box"]/span[@class="news-from"]/text()')[0]
                details=req.xpath('//div[@class="content-l detail"]/p/text()')
                detail='n'.join(details)
                print(h2, author, detail)
                self.save(h2, author, detail)
                return h2, author, detail
            except IndexError:
                print(">>>采集出错需延时,5s后重试..")
                time.sleep(5)
                self.parse_detail(url)


    @staticmethod
    def validate_title(title):
        pattern = r"[/\:*?"<>|]"
        new_title = re.sub(pattern, "_", title)  # 替换为下划线
        return new_title



    def save(self,h2, author, detail):
        with open(f'{h2}.txt','w',encoding='utf-8') as f:
            f.write('%s%s%s%s%s'%(h2,'n',detail,'n',author))

        print(f"保存{h2}.txt文本成功!")


    def get_tasks(self):
        data_list = self.parse_home_list(self.url)
        for item in data_list:
            yield item




if __name__=="__main__":
    url="https://yz.chsi.com.cn/kyzx/jyxd/"
    spider=Spider(url)
    for data in spider.get_tasks():
        print(data)
        

免责声明:代码仅学习使用,勿用于非法用途