爬取全部的校园新闻

 本次作业的要求来自于：https://edu.cnblogs.com/campus/gzcc/GZCC-16SE1/homework/3002

0.从新闻url获取点击次数，并整理成函数

• newsUrl
• newsId(re.search())
• clickUrl(str.format())
• requests.get(clickUrl)
• re.search()/.split()
• str.lstrip(),str.rstrip()
• int
• 整理成函数
• 获取新闻发布时间及类型转换也整理成函数

1.从新闻url获取新闻详情： 字典,anews

2.从列表页的url获取新闻url：列表append(字典) alist

3.生成所页列表页的url并获取全部新闻 ：列表extend(列表) allnews

*每个同学爬学号尾数开始的10个列表页

4.设置合理的爬取间隔

import time

import random

time.sleep(random.random()*3)

5.用pandas做简单的数据处理并保存

保存到csv或excel文件 

newsdf.to_csv(r'F:duym爬虫gzccnews.csv')

import re
from bs4 import BeautifulSoup
import requests
from datetime import datetime
import pandas as pd

#获取点击次数
def click(url):
    #通过正则表达式获取URL中的数字，并获取列表中最后一个元素
    id = re.findall('(d{1,5})',url)[-1]
    clickurl = "http://oa.gzcc.cn/api.php?op=count&id={}&modelid=80".format(id)
    resClick = requests.get(clickurl)
    newsClick = int(resClick.text.split('.html')[-1].lstrip("('").rstrip("');"))
    return newsClick

#获取发布时间、转换datetime类型
def newsdt(showInfo):
    newsDT = showInfo[0] + ' ' + showInfo[1]
    newsDT = newsDT.lstrip('发布时间:')
    dt = datetime.strptime(newsDT,'%Y-%m-%d %H:%M:%S')
    return dt

#获取新闻详情
def anews(url):
    newsDetail = {}
    res = requests.get(url)
    res.encoding = 'utf-8'
    soup = BeautifulSoup(res.text,'html.parser')
    newsDetail['news_1_Title'] = soup.select('.show-title')[0].text
    showInfo = soup.select('.show-info')[0].text.split()
    newsDetail['news_2_datetime'] = newsdt(showInfo)
    newsDetail['news_3_author'] = showInfo[2].split('：')[1]
    newsDetail['news_4_examine'] = showInfo[3][3:]
    newsDetail['news_5_source'] = showInfo[4].split('：')[1]
    newsDetail['news_6_click'] = click(url)
    return newsDetail

#从列表页的url获取新闻url
def alist(listUrl):
    res = requests.get(listUrl)
    res.encoding = 'utf-8'
    soup = BeautifulSoup(res.text,'html.parser')
    newsList = []
    for news in soup.select('li'):
        if len(news.select('.news-list-title'))>0:
            newsUrl = news.select('a')[0]['href']
            newsDesc = news.select('.news-list-description')[0].text
            newsDict = anews(newsUrl)
            newsDict['news_7_Url'] = newsUrl
            newsDict['news_8_description'] = newsDesc
            newsList.append(newsDict)
    return newsList

allnews = []
#获取18~28分页的新闻列表
for i in range(18,28):
    listUrl = 'http://news.gzcc.cn/html/xiaoyuanxinwen/{}.html'.format(i)
    allnews.extend(alist(listUrl))
newsdf = pd.DataFrame(allnews)
print(newsdf)
#保存为本地csv文件
newsdf.to_csv(r'E:PythonAllNewsallNews.csv',encoding='utf-8')