Detailed explanation on sending and receiving front-end json data

from flask import Flask
from flask import jsonify
from flask import request
import json
...

# Log in@("/flask/login", methods=['POST'])
def login():
 data_ = ('data')
 data = (data)
 username = data['username']
 password = data['password']
 rem = False
 if data['remember']:
  rem = True
 return jsonify({"login": (username, password, rem)}) # Return a boolean value

from flask import Flask
from flask import jsonify
from flask import request
import json
...

# Log in@("/flask/login", methods=['POST'])
def login():
 data = request.get_data()
 data = (data)
 username = data['username']
 password = data['password']
 rem = False
 if data['remember']:
  rem = True
 return jsonify({"login": (username, password, rem)}) # Return a boolean value

from flask import Flask
from flask import jsonify
from flask import request

...

# Log in@("/flask/login", methods=['POST'])
def login():
 data = request.get_json()
 username = data['username']
 password = data['password']
 rem = False
 if data['remember']:
  rem = True
 return jsonify({"login": (username, password, rem)}) # Return a boolean value

function login() {
 var username =("username").value;
 var password = ("password").value;
 var remember =("remember").checked;
 var xmlhttp;
 if ()
 {
  // IE7+, Firefox, Chrome, Opera, Safari browser code execution  xmlhttp=new XMLHttpRequest();
 }
 else
 {
  // IE6, IE5 browser code execution  xmlhttp=new ActiveXObject("");
 }
 =function()
 {
  if (===4 && ===200)
  {
   ...
  }
 };

 ("POST","/flask/login",true);
 ("Content-type","application/json");
 //The latter two are very important. I think many of the online uses ("username="+username+"&password="+"). In this way, you need to parse the reception and feel that it is better to send the following format directly. var data = {
  "username": username
  "password": password
  "remember": remember
 };
 var data_json = (data);
 (data_json);
}

 var text = ;
 // Convert json-format strings into js objects through eval() method and parse them to get the content var result = eval("("+text+")");
 if (result) {
    
  } else {
    alert("Please enter the correct username and password");
   }

 $(document).ready(function () {
 var data = {
 "username": "adamin",
 "password": "123456789",
 "remember": true
 }
 $.ajax({
  url: "/flask/login",
  type: "POST",
  data: data,
  success: function () {
   
  }
 })
 })