成功存储数据至server.py，但在尝试检索时出现404未找到的错误提示-PHP中文网问答

我编写了一个 server.py 文件，可以保存学生的姓名、索引号和平均成绩。当我运行client.html文件并输入数据并单击添加学生时，它说学生已成功添加，但是当我输入他的索引以使用获取学生功能时，它说404学生未找到。

这是server.py文件代码：

from flask import Flask, request, jsonify
import pickle

app = Flask(__name__)

try:
    with open('students.pickle', 'rb') as f:
        students = pickle.load(f)
except FileNotFoundError:
    students = {}

@app.route("/")
def index():
    with open("client.html") as f:
        return f.read()

@app.route('/add_student', methods=['POST'])
def add_student():
    name = request.form.get('name')
    surname = request.form.get('surname')
    index = request.form.get('index')
    grade = request.form.get('grade')
    students[index] = {'name': name, 'surname': surname, 'index': index,'grade': grade}

    with open('students.pickle', 'wb') as f:
        pickle.dump(students, f)
        
    return jsonify(message='Student added successfully'), 201

@app.route('/get_student/<int:index>', methods=['GET'])
def get_student(index):
    student = students.get(index)
    if student:
        return jsonify(student)
    else:
        return 'Student not found', 404

if __name__ == '__main__':
    app.run(host='localhost', port=8000, debug=True)

这是 client.html 文件代码：

<!DOCTYPE html>
<html>
<head>
    <script src="https://code.jquery.com/jquery-3.6.0.min.js"></script>
    <script>
        $(document).ready(function() {
            function getStudent() {
                var index = $("#index").val();
                $.ajax({
                    type: "GET",
                    url: "http://localhost:8000/get_student/" + index,
                    success: function(data) {
                        $("#student-info").text(JSON.stringify(data));
                    },
                    error: function() {
                        $("#student-info").text("Student not found");
                    }
                });
            }

            function addStudent() {
                var data = new FormData();
                data.append("name", $("#name").val());
                data.append("surname", $("#surname").val());
                data.append("index", $("#index").val());
                data.append("grade", $("#grade").val());
                $.ajax({
                    type: "POST",
                    url: "http://localhost:8000/add_student",
                    data: data,
                    processData: false,
                    contentType: false,
                    success: function(data) {
                        $("#add-student-result").text("Student added");
                    },
                    error: function() {
                        $("#add-student-result").text("Error adding student");
                    }
                });
            }

            $("#get-student-form").submit(function(e) {
                e.preventDefault();
                getStudent();
            });

            $("#add-student-form").submit(function(e) {
                e.preventDefault();
                addStudent();
            });
        });
    </script>
</head>
<body>
    <form id="get-student-form">
        <label for="index">Index:</label>
        <input type="text" id="index" name="index">
        <button type="submit">Get Student</button>
    </form>
    <div id="student-info"></div>
    <br>
    <form id="add-student-form">
        <label for="name">Name:</label>
        <input type="text" id="name" name="name">
        <br>
        <label for="surname">Surname:</label>
        <input type="text" id="surname" name="surname">
        <br>
        <label for="index">Index:</label>
        <input type="text" id="index" name="index">
        <br>
        <label for="grade">Grade:</label>
        <input type="text" id="grade" name="grade">
        <br>
        <button type="submit">Add Student</button>
    </form>
    <div id="add-student-result"></div>
</body>
</html>