URL Shortener using Flask — with Source Code

Hello guys, in today’s blog we will build a URL Shortener using Flask. This will be an exciting blog, so without any further due, let’s do it…

Read the full blog here — https://machinelearningprojects.net/url-shortener-using-flask/

Checkout the video here — https://youtu.be/LwzsE8Vv-1Y

Sneak Peek at our URL Shortener using Flask

Install required libraries

pip install flask hashids

Code Files For our URL Shortener

Our Project majorly consists of the following 3 code files:

  • app.py
  • index.html
  • stats.html

app.py

# URL Shortener using Flask

import sqlite3
from hashids import Hashids
from flask import Flask, render_template, request, flash, redirect, url_for

app = Flask(__name__)
app.config['SECRET_KEY'] = 'this should be a secret random string'


connection = sqlite3.connect('database.db')

c = connection.cursor()

c.execute('''CREATE TABLE IF NOT EXISTS urls(
id INTEGER PRIMARY KEY AUTOINCREMENT,
created TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
original_url TEXT NOT NULL,
clicks INTEGER NOT NULL DEFAULT 0
)''')

def get_db_connection():
conn = sqlite3.connect('database.db')
conn.row_factory = sqlite3.Row
return conn


hashids = Hashids(min_length=4, salt=app.config['SECRET_KEY'])


@app.route('/', methods=('GET', 'POST'))
def index():
conn = get_db_connection()

if request.method == 'POST':
url = request.form['url']

if not url:
flash('The URL is required!')
return redirect(url_for('index'))

url_data = conn.execute('INSERT INTO urls (original_url) VALUES (?)',(url,))
conn.commit()
conn.close()

url_id = url_data.lastrowid
hashid = hashids.encode(url_id)
short_url = request.host_url + hashid

return render_template('index.html', short_url=short_url)

return render_template('index.html')



@app.route('/<id>')
def url_redirect(id):
conn = get_db_connection()

original_id = hashids.decode(id)
if original_id:
original_id = original_id[0]
url_data = conn.execute('SELECT original_url, clicks FROM urls WHERE id = (?)', (original_id,)).fetchone()
original_url = url_data['original_url']
clicks = url_data['clicks']

conn.execute('UPDATE urls SET clicks = ? WHERE id = ?',(clicks+1, original_id))
conn.commit()
conn.close()
return redirect(original_url)
else:
flash('Invalid URL')
return redirect(url_for('index'))



@app.route('/stats')
def stats():
conn = get_db_connection()
db_urls = conn.execute('SELECT id, created, original_url, clicks FROM urls').fetchall()
conn.close()

urls = []
for url in db_urls:
url = dict(url)
url['short_url'] = request.host_url + hashids.encode(url['id'])
urls.append(url)

return render_template('stats.html', urls=urls)

index.html

<!doctype html>
<html lang="en">

<head>
<!-- Required meta tags -->
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">

<!-- Bootstrap CSS -->
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css"
integrity="sha384-ggOyR0iXCbMQv3Xipma34MD+dH/1fQ784/j6cY/iJTQUOhcWr7x9JvoRxT2MZw1T" crossorigin="anonymous">

<title>Welcome to FlaskShortener</title>
</head>

<body>
<nav class="navbar navbar-expand-md navbar-light bg-light">
<a class="navbar-brand" href="{{ url_for('index')}}">FlaskTodo</a>
<button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarNav"
aria-controls="navbarNav" aria-expanded="false" aria-label="Toggle navigation">
<span class="navbar-toggler-icon"></span>
</button>
<div class="collapse navbar-collapse" id="navbarNav">
<ul class="navbar-nav">
<li class="nav-item active">
<a class="nav-link" href="#">About</a>
</li>

<li class="nav-item active">
<a class="nav-link" href="{{ url_for('stats')}}">Stats</a>
</li>
</ul>
</div>
</nav>
<div class="container">
{% for message in get_flashed_messages() %}
<div class="alert alert-danger">{{ message }}</div>
{% endfor %}

<h1>Welcome to FlaskShortener</h1>
<form method="post">
<div class="form-group">
<label for="url">URL</label>
<input type="text" name="url" placeholder="URL to shorten" class="form-control"
value="{{ request.form['url'] }}" autofocus></input>
</div>

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

{% if short_url %}
<hr>
<span>{{ short_url }}</span><br>
{% endif %}

</div>



<!-- Optional JavaScript -->
<!-- jQuery first, then Popper.js, then Bootstrap JS -->
<script src="https://code.jquery.com/jquery-3.3.1.slim.min.js"
integrity="sha384-q8i/X+965DzO0rT7abK41JStQIAqVgRVzpbzo5smXKp4YfRvH+8abtTE1Pi6jizo"
crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.7/umd/popper.min.js"
integrity="sha384-UO2eT0CpHqdSJQ6hJty5KVphtPhzWj9WO1clHTMGa3JDZwrnQq4sF86dIHNDz0W1"
crossorigin="anonymous"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/js/bootstrap.min.js"
integrity="sha384-JjSmVgyd0p3pXB1rRibZUAYoIIy6OrQ6VrjIEaFf/nJGzIxFDsf4x0xIM+B07jRM"
crossorigin="anonymous"></script>
</body>

</html>

stats.html

<!doctype html>
<html lang="en">

<head>
<!-- Required meta tags -->
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">

<!-- Bootstrap CSS -->
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css"
integrity="sha384-ggOyR0iXCbMQv3Xipma34MD+dH/1fQ784/j6cY/iJTQUOhcWr7x9JvoRxT2MZw1T" crossorigin="anonymous">

<title>Welcome to FlaskShortener</title>
</head>

<body>
<nav class="navbar navbar-expand-md navbar-light bg-light">
<a class="navbar-brand" href="{{ url_for('index')}}">FlaskTodo</a>
<button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarNav"
aria-controls="navbarNav" aria-expanded="false" aria-label="Toggle navigation">
<span class="navbar-toggler-icon"></span>
</button>
<div class="collapse navbar-collapse" id="navbarNav">
<ul class="navbar-nav">
<li class="nav-item active">
<a class="nav-link" href="#">About</a>
</li>

<li class="nav-item active">
<a class="nav-link" href="{{ url_for('stats')}}">Stats</a>
</li>
</ul>
</div>
</nav>
<h1>{% block title %} FlaskShortener Statistics {% endblock %}</h1>
<table class="table">
<thead>
<tr>
<th scope="col">#</th>
<th scope="col">Short</th>
<th scope="col">Original</th>
<th scope="col">Clicks</th>
<th scope="col">Creation Date</th>
</tr>
</thead>
<tbody>
{% for url in urls %}
<tr>
<th scope="row">{{ url['id'] }}</th>
<td>{{ url['short_url'] }}</td>
<td>{{ url['original_url'] }}</td>
<td>{{ url['clicks'] }}</td>
<td>{{ url['created'] }}</td>
</tr>
{% endfor %}
</tbody>
</table>

<!-- Optional JavaScript -->
<!-- jQuery first, then Popper.js, then Bootstrap JS -->
<script src="https://code.jquery.com/jquery-3.3.1.slim.min.js"
integrity="sha384-q8i/X+965DzO0rT7abK41JStQIAqVgRVzpbzo5smXKp4YfRvH+8abtTE1Pi6jizo"
crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.7/umd/popper.min.js"
integrity="sha384-UO2eT0CpHqdSJQ6hJty5KVphtPhzWj9WO1clHTMGa3JDZwrnQq4sF86dIHNDz0W1"
crossorigin="anonymous"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/js/bootstrap.min.js"
integrity="sha384-JjSmVgyd0p3pXB1rRibZUAYoIIy6OrQ6VrjIEaFf/nJGzIxFDsf4x0xIM+B07jRM"
crossorigin="anonymous"></script>
</body>

</html>

Our Final Output

Refer to this article for deploying it online — How to Deploy a Flask app online using Pythonanywhere

And this is how you can create a URL Shortener using Flask…

So this is all for this blog folks. Thanks for reading it and I hope you are taking something with you after reading this and till the next time …

Read my last blog — Create an API in Flask and deploy it online

Check out my other machine learning projects, deep learning projects, computer vision projects, NLP projects, and Flask projects at machinelearningprojects.net.

--

--

Get the Medium app

A button that says 'Download on the App Store', and if clicked it will lead you to the iOS App store
A button that says 'Get it on, Google Play', and if clicked it will lead you to the Google Play store