菜鸟学IT之python网页爬取多页爬取

作业来源：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

import re
url='http://news.gzcc.cn/html/2019/xiaoyuanxinwen_0320/11029.html'
clickurl='http://oa.gzcc.cn/api.php?op=count&id=11029&modelid=80'

re.match('http://news.gzcc.cn/html/2019/xiaoyuanxinwen_0320/(.*).html',url)

re.match('http://news.gzcc.cn/html/2019/xiaoyuanxinwen_0320/(.*).html',url).groups(0)

re.search('/(\d*).html',url).groups(1)

re.findall('(\d+)',url)

结果如下：

1.从新闻url获取新闻详情：字典,anews

import requests
from bs4 import BeautifulSoup
from datetime import datetime
import re

def click(url):
    id=re.findall('(\d{1,5})',url)[-1]
    clickUrl = 'http://oa.gzcc.cn/api.php?op=count&id=11029&modelid=80'.format(id)
    resClick = requests.get(clickUrl)
    newsClick = int(resClick.text.split('.html')[-1].lstrip("('").rstrip("');"))
    return newsClick

def newsdt(showinfo):
    newsDate = showinfo.split()[0].split(':')[1]
    newsTime = showinfo.split()[1]
    newsDT = newsDate+' '+newsTime
    dt = datetime.strptime(newsDT, '%Y-%m-%d %H:%M:%S')
    
    return dt

def anews(url):
    newsDetail = {}
    res = requests.get(url)
    res.encoding ='utf-8'
    soup = BeautifulSoup(res.text,'html.parser')
    newsDetail['nenewsTitle'] =soup.select('.show-title')[0].text
    showinfo = soup.select('.show-info')[0].text
    newsDetail['newsDT']=newsdt(showinfo)
    newsDetail['newsClick'] =click(newsUrl)
    return newsDetail

newsUrl='http://news.gzcc.cn/html/2005/xiaoyuanxinwen_0710/4.html'
anews(newsUrl)

结果：

2.从列表页的url获取新闻url：列表append(字典) alist

获取列表数据

listurl = 'http://news.gzcc.cn/html/xiaoyuanxinwen/'
res = requests.get(listurl)
res.encoding ='utf-8'
soupn = BeautifulSoup(res.text,'html.parser')  

# a=soupn.select('a')
soupn

2.过滤过滤数据，只获取列表的新闻信息

for news in soupn.select('li'):
    if news.select('.news-list-title'):
        print(news)
        newsUrl = news.a['href']
        print(news.a['href'])

3.获取整页信息

def alist(listUrl):
    res = requests.get(listurl)
    res.encoding ='utf-8'
    soup = BeautifulSoup(res.text,'html.parser')
    newsList =[]
    for news in soupn.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['newsUrl'] = newsUrl
            newsDict['description'] = newsDesc
            newsList.append(newsDict)
    return newsList

listUrl = 'http://news.gzcc.cn/html/xiaoyuanxinwen/'
alist(listUrl)

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

获取多页信息

截取以学号尾数开始的10个列表页

listUrl = 'http://news.gzcc.cn/html/xiaoyuanxinwen/'
allnews = alist(listUrl)

for i in range(7,17): #学号为7，截取10页
    listUrl = 'http://news.gzcc.cn/html/xiaoyuanxinwen/{}.html'.format(i)
    allnews.extend(alist(listUrl))

len(allnews)

4.设置合理的爬取间隔

import time

import random

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

import time
import random
listUrl = 'http://news.gzcc.cn/html/xiaoyuanxinwen/'
allnews = alist(listUrl)

for i in range(1,170): #学号为7，截取10页
    listUrl = 'http://news.gzcc.cn/html/xiaoyuanxinwen/{}.html'.format(i)
    allnews.extend(alist(listUrl))
    time.sleep(random.random()*3) #设置每3秒爬取一次