Python - my web application keep displaying “Hello World!”

Question

So, I'm facing an issue here. I have installed Flask and tried to run the code sample in order to test:

from flask import Flask
app = Flask(__name__)

@app.route("/")
def hello():
    return "Hello World!"

So far so good. However, after changing a bit the code within my python web app, when I run it on localhost, the browser opens the previous page with Hello World! . What am I doing wrong here?

Here's my final code in Python :

from flask import Flask, render_template, redirect, url_for, request

from student import Student

students = []

app = Flask(__name__)


@app.route("/", methods=["GET", "POST"])
def students_page():
    if request.method == "POST":
        new_student_id = request.form.get("student-id", "")
        new_student_name = request.form.get("name", "")
        new_student_last_name = request.form.get("last-name", "")

        new_student = Student(name=new_student_name, student_id=new_student_id)
        students.append(new_student)

        return redirect(url_for("students_page"))

    return render_template("index.html", students=students)


if __name__ == "__main__":
    app.run(debug=True)

HTML file code:

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <!-- The above 3 meta tags *must* come first in the head; any other head content must come *after* these tags -->
    <meta name="description" content="">
    <meta name="author" content="">

    <title>A title</title>

    <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous">

    <!-- Optional theme -->
    <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap-theme.min.css" integrity="sha384-rHyoN1iRsVXV4nD0JutlnGaslCJuC7uwjduW9SVrLvRYooPp2bWYgmgJQIXwl/Sp" crossorigin="anonymous">

    <!-- HTML5 shim and Respond.js for IE8 support of HTML5 elements and media queries -->
    <!--[if lt IE 9]>
    <script src="https://oss.maxcdn.com/html5shiv/3.7.3/html5shiv.min.js"></script>
    <script src="https://oss.maxcdn.com/respond/1.4.2/respond.min.js"></script>
    <![endif]-->


    <style>
        body {
            padding-top: 70px;
        }
        footer {
            margin-top: 50px;
            padding-top: 20px;
            padding-bottom: 10px;
            background-color: #f5f5f5;
        }
        .text-muted {
            color: #777;
        }
    </style>
</head>

<body>

<nav class="navbar navbar-inverse navbar-fixed-top">
    <div class="container">
        <div class="navbar-header">
            <button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#navbar"
                    aria-expanded="false" aria-controls="navbar">
                <span class="sr-only">Toggle navigation</span>
                <span class="icon-bar"></span>
                <span class="icon-bar"></span>
                <span class="icon-bar"></span>
            </button>
            <a class="navbar-brand" href="#">App</a>
        </div>
        <div id="navbar" class="collapse navbar-collapse">
            <ul class="nav navbar-nav">
                <li class="active"><a href="#">Home</a></li>
                <li><a href="#students">Students</a></li>
                <li><a href="#about">About</a></li>
            </ul>
        </div><!--/.nav-collapse -->
    </div>
</nav>

<div class="container">

    <div class="jumbotron">
        <h1>A H1</h1>
        <p>A paragraph</p>
    </div>

    <div class="page-header">
        <h1>All Students</h1>
    </div>
    <div class="row">
        <div class="col-md-12">
            <table class="table table-striped">
                <thead>
                <tr>
                    <th>Student ID</th>
                    <th>First Name</th>
                    <th>Last Name</th>
                    <th>Actions</th>
                </tr>
                </thead>
                <tbody>
                {% for student in students %}
                <tr>
                    <td>{{ student.student_id }}</td>
                    <td>{{ student.name }}</td>
                    <td>{{ student.last_name }}</td>
                    <td>
                        <button class="btn btn-primary btn-sm">Edit</button>
                        <button class="btn btn-danger btn-sm">Delete</button>
                    </td>
                </tr>
                {% endfor %}
                </tbody>
            </table>
        </div>

    </div>

    <div class="page-header">
        <h1>Add a Student</h1>
    </div>

    <div class="row">
        <div class="col-md-8">
            <form method="POST">
                <div class="form-group">
                    <label for="student-id">Student ID</label>
                    <input type="number" class="form-control" id="student-id" placeholder="Student ID" name="student-id">
                </div>
                <div class="form-group">
                    <label for="first-name">First Name</label>
                    <input type="text" class="form-control" id="first-name" placeholder="First Name" name="name">
                </div>
                <div class="form-group">
                    <label for="last-name">Last Name</label>
                    <input type="text" class="form-control" id="last-name" placeholder="Last Name" name="last-name">
                </div>

                <button type="submit" class="btn btn-default">Submit</button>
            </form>
        </div>
    </div>

</div>

<footer class="footer">
  <div class="container">
      <p class="text-muted">footer</p>
  </div>
</footer>


<!-- Bootstrap core JavaScript
================================================== -->
<!-- Placed at the end of the document so the pages load faster -->
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.4/jquery.min.js"></script>

<!-- Latest compiled and minified JavaScript -->
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"
        integrity="sha384-Tc5IQib027qvyjSMfHjOMaLkfuWVxZxUPnCJA7l2mCWNIpG9mGCD8wGNIcPD7Txa"
        crossorigin="anonymous"></script>
</body>
</html>

Answer 1

I think you need to "Empty Cache and Hard Reload". Try as below:

Hold F12 and right click on the refresh icon (circular icon on the top left) and select 'Empty Cache and Hard Reload'.

You can find details from here

Answer 2

Well, apparently I was able to overpass this by force stopping my web app to run under localhost directly from PyCharm which initially I thought it's automatically stopping when I close my browser:

Hope will help!

Python - my web application keep displaying “Hello World!”

Question

2 answers

solution1
0 2018-10-25 12:22:40

solution2
0 ACCPTED 2018-12-30 19:03:22

Python - my web application keep displaying “Hello World!”

Question

2 answers

solution1 0 2018-10-25 12:22:40

solution2 0 ACCPTED 2018-12-30 19:03:22

solution1
0 2018-10-25 12:22:40

solution2
0 ACCPTED 2018-12-30 19:03:22