如何以两种方式将 Javascript 连接到 Python 以 JSON 格式共享数据?

2021-12-11 00:00:00 python json web-services javascript sqlite

我正在尝试找出如何使用 JSON 格式在 Python 服务器和 Javascript 客户端之间创建本地连接以获取要检索的数据.特别是，我需要在 HTML 客户端进行一些查询，将这些查询以 JSON 格式发送到服务器，并在 Python 服务器端运行它们以搜索 SQLite 数据库上的数据.从数据库中获取结果后，也将这些结果以 JSON 格式发送回客户端.

I'm trying to find out how to create a local connection between a Python server and a Javascript client using the JSON format for the data to be retrieved. Particularly, I need to make some queries on the HTML client side, send these queries to the server on JSON format and run them on the Python server side to search for data on a SQLite Database. And after getting the results from the database, send those results back to the client in JSON format too.

现在，我只能在 Python 上运行查询并在 JSON 上进行编码，如下所示:

By now, I just can run the query on Python and code it on JSON like this:

import sqlite3 as dbapi
import json

connection = dbapi.connect("C:/folder/database.db")
mycursor = connection.cursor()
mycursor.execute("select * from people")
results = []
for information in mycursor.fetchall():
        results += information

onFormat = json.dumps(results)
print(onFormat)

我知道这段代码做了类似的事情(实际上它运行)，因为它调用服务器上的服务，该服务以 JSON 格式返回数据(但本示例中的服务器不是 Python):

I know this code does something alike (in fact it runs), because it calls a service on a server which returns data in JSON format (but the server in this example is NOT Python):

<html>
    <head>
        <style>img{ height: 100px; float: left; }</style>
        <script src="http://code.jquery.com/jquery-latest.js"></script>
    </head>
    <body>
        <div id="images"></div>
    <script>
      $.getJSON("http://api.flickr.com/services/feeds/photos_public.gne?jsoncallback=?",
      {
        tags: "mount rainier",
        tagmode: "any",
        format: "json"
      },
      function(data) {
        $.each(data.items, function(i,item){
          $("<img/>").attr("src", item.media.m).appendTo("#images");
          if ( i == 3 ) return false;
        });
      });</script>

    </body>
</html>

我需要知道我应该如何(在本地)运行 python 程序才能成为一个可用的正在运行的 web 服务，以及 Javascript 应该如何从 python 服务器检索数据.

What I need is to know how should I run (locally) the python program to be an available running web-service and how should be the Javascript to retrieve the data from the python server.

我到处都在互联网上寻找这个，但我没有在任何地方找到这个答案，因为他们给出的唯一答案是关于如何在 Python 或 Javascript 中编码 JSON，但不能同时连接两者.希望有人能帮我解决这个问题！！！

I've looking for this on internet everywhere but I didn't find this answer anywhere because the only answers they give are on how to code JSON inside Python or inside Javascript but not connecting both. Hope somebody can help me on this!!!

推荐答案

我终于找到了比 Flask 更简单的方法.它是一个名为 Bottle 的 Python 框架，您只需要从官方网站下载该库并将其所有工作目录中的文件以导入库.您也可以使用包含的 setup python 程序安装它，以避免随处携带源代码.然后，为了制作您的 Web 服务服务器，您可以这样编码:

I found finally an easier way than Flask. It's a Python framework called Bottle You only need to download the library from the official web site and put all its files in your working directory in order to import the library. You can also install it using the setup python program included to avoid carrying with the sourcecode everywhere. Then, for making your Web Service Server you can code it like this:

from bottle import hook, response, route, run, static_file, request
import json
import socket
import sqlite3

#These lines are needed for avoiding the "Access-Control-Allow-Origin" errors
@hook('after_request')
def enable_cors():
    response.headers['Access-Control-Allow-Origin'] = '*'

#Note that the text on the route decorator is the name of the resource
# and the name of the function which answers the request could have any name
@route('/examplePage')
def exPage():
    return "<h1>This is an example of web page</h1><hr/><h2>Hope you enjoy it!</h2>"

#If you want to return a JSON you can use a common dict of Python, 
# the conversion to JSON is automatically done by the framework
@route('/sampleJSON', method='GET')
def mySample():
    return { "first": "This is the first", "second": "the second one here", "third": "and finally the third one!" }

#If you have to send parameters, the right sintax is as calling the resoure
# with a kind of path, with the parameters separed with slash ( / ) and they 
# MUST to be written inside the lesser/greater than signs  ( <parameter_name> ) 
@route('/dataQuery/<name>/<age>')
def myQuery(name,age):
    connection= sqlite3.connect("C:/folder/data.db")
    mycursor = connection.cursor()
    mycursor.execute("select * from client where name = ? and age= ?",(name, age))
    results = mycursor.fetchall()
    theQuery = []
    for tuple in results:
        theQuery.append({"name":tuple[0],"age":tuple[1]})
    return json.dumps(theQuery)

#If you want to send images in jpg format you can use this below
@route('/images/<filename:re:.*.jpg>')
def send_image(filename):
    return static_file(filename, root="C:/folder/images", mimetype="image/jpg")

#To send a favicon to a webpage use this below
@route('/favicon.ico')
def favicon():
    return static_file('windowIcon.ico', root="C:/folder/images", mimetype="image/ico")

#And the MOST important line to set this program as a web service provider is this
run(host=socket.gethostname(), port=8000)

最后，您可以通过以下方式在 Javascript 客户端上调用 Bottlepy 应用程序的 REST Web 服务:

Finally, you can call the REST web service of your Bottlepy app on a Javascript client in this way:

var addr = "192.168.1.100"
var port = "8000"

function makeQuery(name, age){
    jQuery.get("http://"+addr+":"+port+"/dataQuery/"+ name+ "/" + age, function(result){
        myRes = jQuery.parseJSON(result);
        toStore= "<table border='2' bordercolor='#397056'><tr><td><strong>name</strong></td><td><strong>age</strong></td></tr>";
        $.each(myRes, function(i, element){
            toStore= toStore+ "<tr><td>"+element.name+"</td><td>" + element.age+ "</td></td></tr>";
        })
        toStore= toStore+ "</table>"
        $('#theDataDiv').text('');
        $('<br/>').appendTo('#theDataDiv');
        $(toStore).appendTo('#theDataDiv');
        $('<br/>').appendTo('#theDataDiv');
    })
}

希望对别人有用

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