【Azure Developer】Python 读取 json文件及过滤出需要的结果

问题描述

首先，有名为 campsites.json 的JSON数据文件，数据格式为

{
    "type": "FeatureCollection",
    "name": "DOC_Campsites",
    "crs": {        "type": "name",        "properties": {            "name": "urn:ogc:def:crs:OGC:1.3:CRS84"        }    },
    "features": [
        {
            "type": "Feature",
            "properties": {
                "OBJECTID": 54996,
                "name": "Rarangi Campsite",
                "place": "Blenheim area",
                "region": "Marlborough",
                "introduction": "Camp next to the beach. Fish, walk, picnic, or simply sit and enjoy the roar of the waves.",
                "campsiteCategory": "Standard",
                "status": "OPEN",
                "numberOfPoweredSites": 0,
                "numberOfUnpoweredSites": 55,
                "bookable": "No",
                "free": null,
                "facilities": "Water supply",
                "activities": null,
                "dogsAllowed": "Dogs with a DOC permit only",
                "landscape": "Coastal",
                "access": "Campervan, Car, Caravan",
                "hasAlerts": "Refer to DOC website for current alerts",
                "introductionThumbnail": "https://www.doc.govt.nz/thumbs/large/link/1b698c516b714b63b30de03203738e17.jpg",
                "staticLink": "https://www.doc.govt.nz/link/f5c4e8776bee486aaa1ae8ebdc1e48f8.aspx",
                "locationString": "Located in Blenheim area",
                "x": 1687530,
                "y": 5417097,
                "assetId": 100030520,
                "dateLoadedToGIS": "2021-05-28T04:15:08Z",
                "GlobalID": "{C02F0A50-9316-459A-ADD9-93518E6677EA}"
            },
            "geometry": {"type": "Point","coordinates": [174.04700047400002,-41.39289982899993]}
        }
, ... ... 
    ]
}

全部的campsites.json文件内容下载地址：https://files.cnblogs.com/files/lulight/campsites.json?t=1655124060

修改下面的 server3.py 文件，以达到目标：当用户在浏览器中输入带有区域名称（例如 http://localhost:8080/Marlborough）的 URL 时，这个python服务器应该查询 region=Marlborough 的区域中的 Campsite category 类别为“Great Walk”的 Name +  staticLink 数据在页面中

server3.py 文件内容：

#Author: Sunil Lal

#This is a simple HTTP server which listens on port 8080, accepts connection request, and processes the client request 
#in sepearte threads. It implements basic service functions (methods) which generate HTTP response to service the HTTP requests. 
#Currently there are 3 service functions; default, welcome and getFile. The process function maps the requet URL pattern to the service function.
#When the requested resource in the URL is empty, the default function is called which currently invokes the welcome function.
#The welcome service function responds with a simple HTTP response: "Welcome to my homepage".
#The getFile service function fetches the requested html or img file and generates an HTTP response containing the file contents and appropriate headers.

#To extend this server's functionality, define your service function(s), and map it to suitable URL pattern in the process function.

#This web server runs on python v3
#Usage: execute this program, open your browser (preferably chrome) and type http://servername:8080
#e.g. if server.py and broswer are running on the same machine, then use http://localhost:8080



from socket import *
import _thread

serverSocket = socket(AF_INET, SOCK_STREAM)

serverPort = 8080
serverSocket.setsockopt(SOL_SOCKET, SO_REUSEADDR, 1)
serverSocket.bind(("", serverPort))

serverSocket.listen(5)
print('The server is running')    
# Server should be up and running and listening to the incoming connections

#Extract the given header value from the HTTP request message
def getHeader(message, header):

    if message.find(header) > -1:
        value = message.split(header)[1].split()[0]
    else:
        value = None

    return value

#service function to fetch the requested file, and send the contents back to the client in a HTTP response.
def getFile(filename):

    try:

        # open and read the file contents. This becomes the body of the HTTP response
        f = open(filename, "rb")
        
        body = f.read()


        header = ("HTTP/1.1 200 OK\r\n\r\n").encode()

    except IOError:

        # Send HTTP response message for resource not found
        header = "HTTP/1.1 404 Not Found\r\n\r\n".encode()
        body = "<html><head></head><body><h1>404 Not Found</h1></body></html>\r\n".encode()

    return header, body

#service function to generate HTTP response with a simple welcome message
def welcome(message):


    header = "HTTP/1.1 200 OK\r\n\r\n".encode()
    body = ("<html><head></head><body><h1>Welcome to my homepage</h1></body></html>\r\n").encode()


    return header, body

#default service function
def default(message):

    header, body = welcome(message)

    return header, body


#We process client request here. The requested resource in the URL is mapped to a service function which generates the HTTP reponse 
#that is eventually returned to the client. 
def process(connectionSocket) :    
    # Receives the request message from the client
    message = connectionSocket.recv(1024).decode()


    if len(message) > 1:


        # Extract the path of the requested object from the message
        # Because the extracted path of the HTTP request includes
        # a character '/', we read the path from the second character
        resource = message.split()[1][1:]

        #map requested resource (contained in the URL) to specific function which generates HTTP response 
        if resource == "":
            responseHeader, responseBody = default(message)
        elif resource == "welcome":
            responseHeader,responseBody = welcome(message)
        else:
            responseHeader,responseBody = getFile(resource)


    # Send the HTTP response header line to the connection socket
    connectionSocket.send(responseHeader)
    # Send the content of the HTTP body (e.g. requested file) to the connection socket
    connectionSocket.send(responseBody)
    # Close the client connection socket
    connectionSocket.close()


#Main web server loop. It simply accepts TCP connections, and get the request processed in seperate threads.
while True:
    
    # Set up a new connection from the client
    connectionSocket, addr = serverSocket.accept()
    #Clients timeout after 60 seconds of inactivity and must reconnect.
    connectionSocket.settimeout(60)
    # start new thread to handle incoming request
    _thread.start_new_thread(process,(connectionSocket,))

问题解答

在server3.py 文件中，实现了默认Default，welcome 和 getFile 方法，当访问URL为 http://localhost:8080 时，调用default方法，输出 Welcome to my homepage 信息。同理，当访问URL为  http://localhost:8080/welcome 时,调用welcome方法，同样输出 Welcome to my homepage 信息。 而 getFile 方法，则是读取指定的文件，输出文件内容。所以，本题最重要的代码部分为 getFile方法实现。

当用户在浏览器中输入带有区域名称（例如 http://localhost:8080/Marlborough）的 URL 时，这个python服务器应该查询 region=Marlborough 的区域中的 Campsite category 类别为“Great Walk”的 Name +  staticLink 数据在页面中

第一步：引入 JSON 包

import json

第二步：定义 region 和 campsiteCategory的过滤条件 condition1 和 condition2，以及指定filename为 campsites.json (因为这里只是完成题目，所以硬编码在代码中)

        filename = "campsites.json"
        condition1 = "Marlborough"
        condition2 = "Basic"  # "Great Walk"

第三步：开始使用Json.load文件中的数据，把内容转换为 dict对象，然后根据 JSON格式，读取 features 列表，通过for 循环来一条一条的判断 condtion1 和 condition 2，满足条件，通过html拼接为一个Table

def getFile(regionname):

    try:
        filename = "campsites.json"
        condition1 = "Marlborough"
        condition2 = "Basic"  # "Great Walk"
        # open and read the file contents. This becomes the body of the HTTP response
        f = open(filename, "rb")
        jdata = json.load(f)

        # 查询region=Marlborough的区域中的Campsite category类别为“Great Walk”的Name , site总数并返回
        # region=Marlborough
        ## campsiteCategory =="Great Walk";

        #         print(jdata['name']);
        #         print(jdata['features'][1]['properties']['region'])
        #         print(type(jdata['features'][1]))

        outputTable = ""
        index = 0
        for fs in jdata['features']:
            if fs['properties']['region'] == condition1 and fs['properties']['campsiteCategory'] == condition2:
                outputTable += "<tr><td>" + \
                    fs['properties']['name']+"</td><td>" + \
                    fs['properties']['staticLink']+"</td></tr>"
                # print(fs['properties']['campsiteCategory'])
                index += 1

        body = ("<html><head></head><body><h1>Welcome to my homepage</h1><br><h2>Total row is " +
                str(index)+"</h2><br><table>"+outputTable+"</table></body></html>\r\n").encode()

        header = ("HTTP/1.1 200 OK\r\n\r\n").encode()

    except IOError:

        # Send HTTP response message for resource not found
        header = "HTTP/1.1 404 Not Found\r\n\r\n".encode()
        body = "<html><head></head><body><h1>404 Not Found</h1></body></html>\r\n".encode()

    return header, body

第四步：运行 python server3.py， 检验结果

> python server3.py

因为 campsites.json 数据源中，没有同时满足 region =="Marlborough"  和 campsiteCategory =="Great Walk" 的数据。

所以为了展示页面效果，修改了过滤条件为：

def getFile(regionname):

    try:
        filename = "campsites.json"
        condition1 = regionname; # "Marlborough"
        condition2 = "Basic"  # "Great Walk"

再次测试的效果如下：

 【END】

附录：完整的Server3.py 代码

# Author: Sunil Lal

# This is a simple HTTP server which listens on port 8080, accepts connection request, and processes the client request
# in sepearte threads. It implements basic service functions (methods) which generate HTTP response to service the HTTP requests.
# Currently there are 3 service functions; default, welcome and getFile. The process function maps the requet URL pattern to the service function.
# When the requested resource in the URL is empty, the default function is called which currently invokes the welcome function.
# The welcome service function responds with a simple HTTP response: "Welcome to my homepage".
# The getFile service function fetches the requested html or img file and generates an HTTP response containing the file contents and appropriate headers.

# To extend this server's functionality, define your service function(s), and map it to suitable URL pattern in the process function.

# This web server runs on python v3
# Usage: execute this program, open your browser (preferably chrome) and type http://servername:8080
# e.g. if server.py and broswer are running on the same machine, then use http://localhost:8080


from socket import *
import _thread
import json

serverSocket = socket(AF_INET, SOCK_STREAM)

serverPort = 8080
serverSocket.setsockopt(SOL_SOCKET, SO_REUSEADDR, 1)
serverSocket.bind(("", serverPort))

serverSocket.listen(5)
print('The server is running')
# Server should be up and running and listening to the incoming connections

# Extract the given header value from the HTTP request message


def getHeader(message, header):

    if message.find(header) > -1:
        value = message.split(header)[1].split()[0]
    else:
        value = None

    return value

# service function to fetch the requested file, and send the contents back to the client in a HTTP response.


def getFile(regionname):

    try:
        filename = "campsites.json"
        condition1 = regionname; # "Marlborough"
        condition2 = "Basic"  # "Great Walk"
        # open and read the file contents. This becomes the body of the HTTP response
        f = open(filename, "rb")
        #body = f.read()
        jdata = json.load(f)

        # 查询region=Marlborough的区域中的Campsite category类别为“Great Walk”的Name , site总数并返回
        # region=Marlborough
        ## campsiteCategory =="Great Walk";

        #         print(jdata['name']);
        #         print(jdata['crs']);
        #         print(jdata['features'][1]['properties']['region'])
        #         print(jdata['features'][1]['properties']['campsiteCategory'])
        #         print(type(jdata['features'][1]))

        outputTable = ""
        index = 0
        for fs in jdata['features']:
            if fs['properties']['region'] == condition1 and fs['properties']['campsiteCategory'] == condition2:
                outputTable += "<tr><td>" + \
                    fs['properties']['name']+"</td><td>" + \
                    fs['properties']['staticLink']+"</td></tr>"
                # print(index)
                # print(fs['properties']['region'])
                # print(fs['properties']['campsiteCategory'])
                index += 1
        #d = filter(lambda x:x.index)
        #print(outputTable)
        body = ("<html><head></head><body><h1>Welcome to my homepage</h1><br><h2>Total row is " +
                str(index)+"</h2><br><table>"+outputTable+"</table></body></html>\r\n").encode()

        header = ("HTTP/1.1 200 OK\r\n\r\n").encode()

    except IOError:

        # Send HTTP response message for resource not found
        header = "HTTP/1.1 404 Not Found\r\n\r\n".encode()
        body = "<html><head></head><body><h1>404 Not Found</h1></body></html>\r\n".encode()

    return header, body

# service function to generate HTTP response with a simple welcome message


def welcome(message):

    header = "HTTP/1.1 200 OK\r\n\r\n".encode()
    body = ("<html><head></head><body><h1>Welcome to my homepage</h1></body></html>\r\n").encode()

    return header, body

# default service function


def default(message):

    header, body = welcome(message)

    return header, body


# We process client request here. The requested resource in the URL is mapped to a service function which generates the HTTP reponse
# that is eventually returned to the client.
def process(connectionSocket):
    # Receives the request message from the client
    message = connectionSocket.recv(1024).decode()

    if len(message) > 1:

        # Extract the path of the requested object from the message
        # Because the extracted path of the HTTP request includes
        # a character '/', we read the path from the second character
        resource = message.split()[1][1:]

        # map requested resource (contained in the URL) to specific function which generates HTTP response
        if resource == "":
            responseHeader, responseBody = default(message)
        elif resource == "welcome":
            responseHeader, responseBody = welcome(message)
        else:
            responseHeader, responseBody = getFile(resource)

    # Send the HTTP response header line to the connection socket
    connectionSocket.send(responseHeader)
    # Send the content of the HTTP body (e.g. requested file) to the connection socket
    connectionSocket.send(responseBody)
    # Close the client connection socket
    connectionSocket.close()


# Main web server loop. It simply accepts TCP connections, and get the request processed in seperate threads.
while True:

    # Set up a new connection from the client
    connectionSocket, addr = serverSocket.accept()
    # Clients timeout after 60 seconds of inactivity and must reconnect.
    connectionSocket.settimeout(60)
    # start new thread to handle incoming request
    _thread.start_new_thread(process, (connectionSocket,))

参考资料

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