所以，我做了一个网站，使博客。它一直给我错误：

TypeError: The view function for 'createblog' did not return a valid response. The function either returned None or ended without a return statement.

但问题是在我的python代码中，我的createblogs路由结构如下：

@app.route("/createblog", methods=["POST"])
def createblog():
    title = request.args.get("title")
    description = request.args.get("description")
    content = request.args.get("content")
    username = request.args.get("username")
    password = request.args.get("password")

    if not title or not description or not content or not username or not password:
        return

    cursor.execute("INSERT INTO blogs (poster_id, title, description, content) VALUES ((SELECT id FROM users WHERE username=? AND password=?), ?, ?, ?)", (username, password, title, description, content))
    connection.commit()

    return jsonify(status=200)

如你所见，我有return jsonify(status=200)。这真的很奇怪，因为我用了同样的技巧登录，而且成功了！

@app.route("/register", methods=["POST"])
def register():
    username = request.form.get("username")
    password = request.form.get("password")

    print(username, password)

    if not username or not password:
        return

    cursor.execute(
        "INSERT INTO users (username, password) VALUES (?, ?)", (username, password))
    connection.commit()

    return jsonify(status=200)

我的javascript AJAX 代码：

const xhttp = new XMLHttpRequest();
            const postObject = {
                username: username.value,
                password: password.value,
                title: title.value,
                description: description.value,
                content: content.value,
            }
            const post = JSON.stringify(postObject);
            xhttp.open("POST", "/createblog", true);
            xhttp.setRequestHeader("Content-Type", "application/json");
            xhttp.send(post);

我已经排除了所有其他原因（例如：HTML）与此问题无关。非常感谢帮助！
我试图重新启动我的开发服务器，希望这会改变一些事情，但没有！这个问题一直存在。然后我试着在stackoverflow上发布一个查询，希望隧道中的光在这个比喻中是对我给出的问题的解释。