由于网页结构跟之前有变化，还不是很熟悉。代码待完善，问题记录：

腾讯新闻二级网页内容爬取有问题。

链家网站头文件没有用到。

爬取一条腾讯视频的header内容，存入txt。要求：

包含网页链接

包含title

包含所有headers信息

import requests

from bs4 import BeautifulSoup

u = 'http://news.qq.com/a/20170205/023923.htm'

r = requests.get(url = u)

headers = r.headers #获取网页头部信息

#print(headers)

soup = BeautifulSoup(r.text,'lxml')

title = soup.title.text #获取网页title内容

#print(title)

f = open('C:\\Users\\Administrator\\Desktop\\lianxi\\header.txt','w',encoding='utf8')

f.seek(0)

# 创建一个txt文件

f.write('爬取网页：'+str(u)+'\n')

f.write('新闻标题为：'+title+'\n')

for i in headers:

lst = [i,':',headers[i],'\n']

f.writelines(lst)

f.close()

print('finished!')

爬取腾讯新闻网站上，某一天的某类新闻标题。要求：

开头：‘XX年XX月XX日腾讯新闻’

包括新闻标题和网址

(爬取每一条新闻的内容(二级标题))

import requests

from bs4 import BeautifulSoup

import re

u = 'http://news.qq.com/world_index.shtml'

r = requests.get(url = u)

soup = BeautifulSoup(r.text,'lxml')

f = open('C:\\Users\\Administrator\\Desktop\\lianxi\\news.txt','w',encoding='utf8')

f.seek(0)

# 创建一个txt文件

f.write('2018年8月26日腾讯新闻\n')

news = soup.find_all('a',href=re.compile('http://news.qq.com/a/20180825/'))

#print(news)

for i in news:

#print(i)

txt = i.text.strip()#strip() 用于去掉前后空格

if txt =='':

continue

else:

lst = [txt,',','url=',i.attrs['href']]

f.writelines(lst)

f.close()

print('finished!')

修改

import requests

from bs4 import BeautifulSoup

import re

u = 'http://news.qq.com/world_index.shtml'

r = requests.get(url = u)

soup = BeautifulSoup(r.text,'lxml')

f = open('C:\\Users\\Administrator\\Desktop\\lianxi\\news.txt','w',encoding='utf8')

f.seek(0)

# 创建一个txt文件

f.write('2018年8月26日腾讯新闻\n')

news = soup.find_all('a',href=re.compile('//new.qq.com/omn/20180826'))

#print(news)

for i in news:

#print(i)

txt = i.text.strip()#strip() 用于去掉前后空格

if txt =='':

continue

else:

lst = [txt,',','url=','http:',i.attrs['href'],'\n']

f.writelines(lst)

f.close()

print('finished!')

添加正文内容：

import requests

from bs4 import BeautifulSoup

import re

u = 'http://news.qq.com/world_index.shtml'

r = requests.get(url = u)

soup = BeautifulSoup(r.text,'lxml')

f = open('C:\\Users\\Administrator\\Desktop\\lianxi\\news2.txt','w',encoding='utf8')

f.seek(0)

# 创建一个txt文件

f.write('2018年8月26日腾讯新闻\n')

news = soup.find_all('a',href=re.compile('http://news.qq.com/a/2018'))

#print(news)

for i in news:

#print(i)

txt = i.text.strip()#strip() 用于去掉前后空格

if txt =='':

continue

else:

ul = i.attrs['href']

ur = requests.get(url = ul)

usoup = BeautifulSoup(ur.text,'lxml')

f.write(txt+'\n')

#打印正文

f.write('正文如下：\n')

if usoup.body.attrs[id]=='P-QQ':#排除图片新闻

continue

else:

p = usoup.find('div',id="Cnt-Main-Article-QQ").find_all('p')

for i in p:

print(i.text)

f.write(i.text+'\n')

f.write('\n')

f.close()

print('finished!')

爬虫正确的习惯和逻辑

函数式爬取

用浏览器去访问，headers信息

r = request.get(url='...',headers={...})以浏览器的形式向网页进行请求

头部信息

headers = input("粘贴头部信息：")

lst = headers.split('\n')

m=[]

for i in lst:

key = i.split(':')[0]

value = i.split(':')[1]

m.append([str(key),str(value)])

print(dict(m))

def header_format(h):

"""

函数用于转译网页headers信息

h：输入的headers信息

"""

h = input("粘贴头部信息：")

lst = h.split('\n')

m=[]

for i in lst:

key = i.split(':')[0]

value = i.split(':')[1]

m.append([str(key),str(value)])

return(dict(m))

print(header_format(headers))

用函数式写法的优点：

阅读性更强

函数的可复制性

便于修改

爬取一条腾讯视频的header内容，存入txt。函数式编写：

包含网页链接

包含title

包含所有headers信息

爬取链家二手房数据-深圳

import requests

from bs4 import BeautifulSoup

import re

def url_analysis(u, h, s, n):

'''

用于分析网页，最后得到一个含有二级网址的标签列表

u：起始网址

h：头部信息

s：二级网址包含特定字段

n：页码

'''

url_lst=[]

for i in range(1,n+1):

if i == 1:

r = requests.get(url=u+'nb1rs深圳/')

else:

r = requests.get(url=u+'pg'+str(i)+'nb1rs深圳/')

soup = BeautifulSoup(r.text,'lxml')

r2 = soup.find_all('a',href=re.compile(s))

for j in r2:

r3 = j.attrs['href']

url_lst.append(r3)

return(url_lst)

def content(u,h):

'''

爬取网页标签信息

u：爬取的二级网址

h：头部信息

'''

r = requests.get(url=u)

r.encodinge = 'utf-8'

soup = BeautifulSoup(r.text,'lxml')

t = soup.title.text #爬取标题

toprice = soup.find('div',class_='price').find('span',class_='total').text

unprice = soup.find('div',class_='unitPrice').find('span',class_='unitPriceValue').text

area = soup.find('div',class_='area').find('div',class_='mainInfo').text

base = soup.find('div',class_='base').find('div',class_='content').find_all('li')

year = base[-1].text

pattern = 'resblockPosition:\'(.*?)\',' #.*?任意字符

position =re.search(pattern,r.text).group(1)

lng = position.split(',')[0]

lat = position.split(',')[1]

return([t,',', toprice,',', unprice,',', area,',', year,',',lng,',',lat,'\n'])

if __name__ == '__main__': #main函数

web_u = 'https://sz.lianjia.com/ershoufang/'

web_h = {

'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8',

'Accept-Encoding': 'gzip, deflate, br',

'Accept-Language': 'zh-CN,zh;q=0.9',

'Connection': 'keep-alive',

'Cookie': 'TY_SESSION_ID=93f5b43a-5dc9-4d96-b57a-a4eb78f8dc15; lianjia_uuid=614ed9e0-dc25-421f-ba8b-141c574dbb47; _smt_uid=5b80defd.8430805; UM_distinctid=1656f670d3e4ff-02814a7ed21053-b34356b-1fa400-1656f670d3fdd7; _jzqx=1.1535172349.1535172349.1.jzqsr=bj%2Elianjia%2Ecom|jzqct=/.-; _ga=GA1.2.50227061.1535172352; ljref=pc_sem_baidu_ppzq_x; lianjia_ssid=dbe87b29-353a-45c2-97cf-aae666e2771b; Hm_lvt_9152f8221cb6243a53c83b956842be8a=1535172349,1535201139,1535358484; _jzqa=1.3976151446564617700.1535172349.1535201139.1535358484.3; _jzqc=1; _jzqy=1.1535201139.1535358484.1.jzqsr=baidu|jzqct=%E9%93%BE%E5%AE%B6%E7%BD%91.-; _jzqckmp=1; _gid=GA1.2.1182771159.1535358486; select_city=440300; all-lj=c32edd623b8a5a59c7de54c92107bb6c; _qzjc=1; CNZZDATA1255849469=275538323-1535355329-%7C1535355329; CNZZDATA1254525948=1806440598-1535354494-%7C1535354494; CNZZDATA1255633284=72361912-1535358081-%7C1535358081; CNZZDATA1255604082=1229464985-1535356409-%7C1535356409; Hm_lpvt_9152f8221cb6243a53c83b956842be8a=1535359605; _qzja=1.1736056849.1535358739249.1535358739249.1535358739249.1535359600160.1535359605575.0.0.0.10.1; _qzjb=1.1535358739249.10.0.0.0; _qzjto=10.1.0; _jzqb=1.15.10.1535358484.1',

'Host': 'sz.lianjia.com',

'Referer': 'https',

'Upgrade-Insecure-Requests': '1',

'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.181 Safari/537.36'

}

web_s = 'https://sz.lianjia.com/ershoufang/105'

web_n = 3

f = open('C:\\Users\\Administrator\\Desktop\\lianxi\\lianjia.txt','w')

f.seek(0)

f.write('title,total_price万元,unprice元/平方米,area平方米,产权年限,lng,lat\n')

for i in url_analysis(web_u, web_h, web_s, web_n):

data = content(i,web_h)

f.writelines(data)

print(data)

f.close()

print('finished!')