python爬虫今日头条街拍美图开发背景_分析Ajax请求并抓取今日头条街拍美图：爬取详情

from urllib.parse import urlencode

import re

from requests.exceptions import RequestException

from bs4 import BeautifulSoup

import requests

import json

def get_page_index(offset,keyword):#定义一个函数用于获取索引页信息

data = {

'offset': offset,

'format': 'json',

'keyword': keyword,

'autoload': 'true',

'count': '20',

'cur_tab': '3'

}

# cur_tab为3指的是图集板块，数过来第三个,若为1则指代综合板块

#count 数量

url = '/search_content/?' + urlencode(data) #urlencode可将字典对象转化为url的请求参数

headers = {

'User-Agent':'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/55.0.2883.87 Safari/537.36'

}

try:

response = requests.get(url,headers=headers)

if response.status_code == 200:

return response.text

else:

return None

except RequestException:

print('请求索引页出错')

return None

def parse_page_index(html):#定义一个函数解析索引页信息，返回一个包含详情页url的迭代器

data = json.loads(html)#将字符串转化为一个对象(字典)

if data and 'data' in data.keys():#判断data是否为空，同时要满足键里面有‘data’

for item in data.get('data'):#获取字典中key为‘data’的对应的值，这个值data.get('data')为一个容量为20的列表，列表的元素为字典

yield item.get('article_url')#获取字典中key为‘article_url’的对应的值，即网址

def get_page_detail(url):#定义一个函数用于得到详情页下的信息

try:

response = requests.get(url)

if response.status_code == 200:

return response.text

else:

return None

except RequestException:

print('请求详情页出错')

return None

def parse_page_detail(html):#定义解析详情页的方法

soup = BeautifulSoup(html,'lxml')

title = soup.select('title')[0].get_text()

print(title)

'''

image_pattern = pile('gallery: (.*?),\n siblingList',re.S)

result = re.search(image_pattern,html)

if result:

print(result.group(1))

'''

def main():

html = get_page_index('0','街拍')

for url in parse_page_index(html):#parse_page_index(html)返回的是一个迭代器，每次输出一个网址

print(url)

html = get_page_detail(url)

if html:

parse_page_detail(html)

#print(url)

if __name__ == '__main__':

main()

python爬虫今日头条街拍美图开发背景_分析Ajax请求并抓取今日头条街拍美图：爬取详情页的url与实际页面上显示不符...