Python爬取全国各地区疫情风险等级

需求

通过爬虫取得国家官网各地区疫情风险等级,存入电子表格最终如下:

数据来源

http://bmfw.www.gov.cn/yqfxdjcx/risk.html

分析网页

1. 页面结构
   上部:有截至时间,有三个按键:高\中\低.点击可以切换中部的信息
   中部:风险地区信息
   下部:翻页

2. 确定请求方式
   因为有翻页按钮,猜想应该是用ajax更新数据
   打开F12,点<网络>,清除一下之前的内容,刷新一下
   
   
   

3. 分析请求信息

   url=http://bmfw.www.gov.cn/bjww/interface/interfaceJson
   
   #请求方式为:POST
   
   #请求头
   headers={
   	Accept: application/json, text/plain, */*
   	Accept-Encoding: gzip, deflate
   	Accept-Language: zh-CN,zh;q=0.9
   	Connection: keep-alive
   	Content-Length: 235
   	Content-Type: application/json;charset=UTF-8
   	Cookie: wdcid=57661336733ee69d; _gscu_1088464070=62382713kmnu2p11; __auc=5e75e3b61830dbb29f71ed50e8e; wdses=7e7e0e45f5b9f4e6; _gscbrs_1088464070=1; __asc=578b530b18312ed51c75133a6b5; acw_tc=2760823f16624698875982607ee72639a46b54881093f71cc7ab12b65f0a17; wdlast=1662469913; _gscs_1088464070=62469886ezpysq11|pv:2; SERVERID=edf8bc70025336506334b22603ae1cc6|1662469904|1662469877
   	Host: bmfw.www.gov.cn
   	Origin: http://bmfw.www.gov.cn
   	Referer: http://bmfw.www.gov.cn/yqfxdjcx/risk.html
   	User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/103.0.0.0 Safari/537.36
   	x-wif-nonce: QkjjtiLM2dCratiA
   	x-wif-paasid: smt-application
   	x-wif-signature: B80277094A20F7C04C735C8413BE2B014332114512BFB51BADD30E21D5C368D9
   	x-wif-timestamp: 1662469914
   }
   
   #POST请求的数据
   from_data={
   	"key":"3C502C97ABDA40D0A60FBEE50FAAD1DA",
   	"appId":"NcApplication",
   	"paasHeader":"zdww",
   	"timestampHeader":"1662469914",
   	"nonceHeader":"123456789abcdefg",
   	"signatureHeader":"B0BF67E09448D9A8A6C0538B259E715FD51CB51FCD6822E85000C2196354EB0B"
   }
   

   大多数都是常规项目请求.重点分析:
   x-wif-nonce
   x-wif-paasid
   x-wif-signature
   x-wif-timestampy

   timestampHeader
   signatureHeader

4. 确认请求头参数
   先在<源代码 >右边的里输入接口的后半段地址:
   /bjww/interface/interfaceJson,并刷新页面,他会断下来,然后看<作用或>,如果<作用域>里显示有"/bjww/interface/interfaceJson",就可以在里面查看headers等数据
   
   

   上图可见headers只验证
   Accept
   Content-Type
   x-wif-nonce
   x-wif-paasid
   x-wif-signature
   x-wif-timestamp
   使用的是POST请求,请求数据是字符串,字符串中是字典.

5. 分析JS
   5.1 搜索x-wif-nonce等关键字
   在<网络>下按Ctrl+F调出搜索窗口,搜x-wif-nonce
   
   找到2个JS,3个地方
   先点第1.2个JS:
   
   这里已经注释丢了,肯定不是.
   看第3个JS:
   显然就是我们要找的:
   javascript function p(t) { if (!t.commonHeaders) return t; var e = o.value , n = CryptoJS.SHA256(e + "fTN2pfuisxTavbTuYVSsNJHetwq5bJvCQkjjtiLM2dCratiA" + e).toString(CryptoJS.enc.Hex).toUpperCase(); return Object.assign(t.headers, { "x-wif-nonce": "QkjjtiLM2dCratiA", "x-wif-paasid": "smt-application", "x-wif-signature": n, "x-wif-timestamp": e }), t }
   x-wif-nonce和x-wif-paasid是固定值,分别是:“QkjjtiLM2dCratiA"和"smt-application”
   x-wif-signature和x-wif-timestamp是一个对象n,e,可以在这里下一个断点,查看他们:
   

   e是一个时间戳
   n是SHA(e+"fTN2pfuisxTavbTuYVSsNJHetwq5bJvCQkjjtiLM2dCratiA" + e)
   

   这里再进一步验证SHA256是否是标准算法,上图紫框是网页算出来的字串:
   
   可见这里使用的是标准SHA256算法.
   5.2搜索timestampHeader
   在<网络>里搜索timestampHeader
   

   timestampHeader为时间戳
   signatureHeader是SHA(timestampHeader+'23y0ufFl5YxIyGrI8hWRUZmKkvtSjLQA'+'123456789abcdefg'+timestampHeader)
   

编写代码

1.爬虫代码

import hashlib
import os
import requests
import time
import sys
import json
import csv

#显示某等级地区的小计
def show_level_count(x_list):
    j=0
    for i in range(len(x_list)):
        j+=len (x_list[i]["communitys"])
    print(j)
    return j

def writer_to_csv(risk_txt):
    risk_json = json.loads(risk_txt)
    
    so_far_time = risk_json["data"]["end_update_time"]
    
    highlist = risk_json["data"]["highlist"]
    middlelist = risk_json["data"]["middlelist"]
    lowlist = risk_json["data"]["lowlist"]
    
    encoding='utf_8_sig'
    f = open('risk_data_' + so_far_time + '.csv','w', encoding=encoding,newline='')
    csv_writer = csv.writer(f)
    
    level_dict={}    
    level_dict["高风险"]=highlist
    level_dict["中风险"]=middlelist
    level_dict["低风险"]=lowlist

  
    for level in  level_dict.keys():
        risk_level = level
        for i in range(len(level_dict[level])):
            province = level_dict[level][i]["province"]
            city = level_dict[level][i]["city"]
            county = level_dict[level][i]["county"]
            for j in range(len(level_dict[level][i]["communitys"])):
                csv_writer.writerow(
                    [risk_level, province, city, county, level_dict[level][i]["communitys"][j]])
    # write_to_csv_file(csv_writer, highlist, "高风险")
    # write_to_csv_file(csv_writer, middlelist, "中风险")
    # write_to_csv_file(csv_writer, lowlist, "低风险")
    f.close()
    
    print("写入risk_data.csv完成.")

def get_risk_area_data():
    timestamp = str(int(time.time()))
    # timestamp = '1662646358'

    x_wif_timestamp = timestamp
    timestampHeader = timestamp

    x_wif_nonce = 'QkjjtiLM2dCratiA'
    x_wif_paasid = 'smt-application'

    x_wif_signature_str = timestamp + \
        'fTN2pfuisxTavbTuYVSsNJHetwq5bJvCQkjjtiLM2dCratiA'+timestamp
    x_wif_signature = hashlib.sha256(
        x_wif_signature_str.encode('utf-8')).hexdigest().upper()

    signatureHeader_str = timestamp + \
        '23y0ufFl5YxIyGrI8hWRUZmKkvtSjLQA'+'123456789abcdefg'+timestamp
    signatureHeader = hashlib.sha256(
        signatureHeader_str.encode('utf-8')).hexdigest().upper()

    url = 'http://bmfw.www.gov.cn/bjww/interface/interfaceJson'

    headerss = {
        'Accept': "application/json, text/plain, */*",
        'Content-Type': "application/json;charset=utf-8",
        'x-wif-nonce': "QkjjtiLM2dCratiA",
        'x-wif-paasid': "smt-application",
        'x-wif-signature': x_wif_signature,
        'x-wif-timestamp': x_wif_timestamp,
    }

    From_data = "{\"key\":\"3C502C97ABDA40D0A60FBEE50FAAD1DA\",\
    \"appId\":\"NcApplication\",\"paasHeader\":\"zdww\",\
    \"timestampHeader\":\"" + timestampHeader + "\",\
    \"nonceHeader\":\"123456789abcdefg\",\"signatureHeader\":\"" + signatureHeader + "\"}"
    # print(From_data)

    response = requests.post(url=url, data=From_data, headers=headerss)
    if not response.status_code == 200:
        # print(response.status_code)
        return "", response.status_code

    # print(response.text)    
    return response.text.replace('\u2022', ''), response.status_code


if __name__ == '__main__':
    risk_data=get_risk_area_data()
    if risk_data[1]==200:    
        with open('./risk_data.json', 'w',encoding='utf-8') as f:
            f.write(risk_data[0])
        print("写入risk_data.log完成.")

    f = open('risk_data.json', 'r', encoding='utf-8')
    risk_txt = f.read()
    f.close()

    writer_to_csv(risk_txt)
    
    print('全部程序完成,请勿频繁使用!')
    os.system('pause')