ZeroByteCode

Posted on Jul 22

How to Create a Simple URL Shortener Tool with Python

#python #flask #urlshortener #programming

A URL shortener tool allows users to take a long URL and convert it into a shorter, more manageable link. We can build a simple version of this tool using Python and Flask, a lightweight web framework.

Prerequisites

Before starting, ensure you have the following:

Python installed on your system (Python 3.6+ is recommended).
Flask installed. You can install Flask using pip.

Step 1: Setting Up Your Environment

First, you need to create a virtual environment and install Flask. Open your terminal and run the following commands:

# Create a virtual environment
python -m venv myenv

# Activate the virtual environment
# On Windows
myenv\Scripts\activate
# On macOS/Linux
source myenv/bin/activate

# Install Flask
pip install Flask

Step 2: Writing the Code

Create a directory for your project, e.g., url_shortener, and inside it, create a Python file called app.py. We'll break down the code into sections.

Importing Required Libraries

from flask import Flask, request, redirect, url_for
import string
import random

Setting Up Flask App and Database

We'll use a simple in-memory dictionary to store the URL mappings. For a more robust solution, you might use a database like SQLite or PostgreSQL.

app = Flask(__name__)
url_mapping = {}

Function to Generate Short URLs

We'll create a function that generates a short URL key.

def generate_short_url():
    characters = string.ascii_letters + string.digits
    short_url = ''.join(random.choice(characters) for _ in range(6))
    return short_url

Route to Handle URL Shortening

This route will take a long URL from the user and return a shortened version.

@app.route('/shorten', methods=['POST'])
def shorten_url():
    original_url = request.form['url']
    short_url = generate_short_url()
    url_mapping[short_url] = original_url
    return f'Shortened URL: {request.host_url}{short_url}'

Route to Redirect Short URLs

This route will redirect users from the short URL to the original long URL.

@app.route('/<short_url>')
def redirect_url(short_url):
    original_url = url_mapping.get(short_url)
    if original_url:
        return redirect(original_url)
    else:
        return 'URL not found', 404

Main Function to Run the App

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

Step 3: Running the Tool

Save your app.py file and run it from the terminal:

python app.py

The Flask development server will start, and you can access the URL shortener tool by navigating to http://127.0.0.1:5000 in your web browser.

Step 4: Testing the Tool

To shorten a URL, you can use a tool like curl or a simple HTML form. Here's a basic HTML form for testing:

<!DOCTYPE html>
<html>
<head>
    <title>URL Shortener</title>
</head>
<body>
    <form action="http://127.0.0.1:5000/shorten" method="post">
        <label for="url">Enter URL to shorten:</label>
        <input type="text" id="url" name="url">
        <input type="submit" value="Shorten">
    </form>
</body>
</html>

Save this HTML code as index.html and open it in your web browser. Enter a URL to shorten and submit the form. You should see a shortened URL that you can use to test the redirection functionality.

Conclusion

By following these steps, you can create a simple URL shortener tool using Python and Flask.

This tool can be further enhanced with additional features such as user authentication, analytics, and a database for storing URL mappings persistently.

Alternatively you can also read how to create a simple URL Shortener tool using Python.

Want to learn more? Explore programming articles, tips and tricks on ZeroByteCode.

Top comments (2)

Stokry • Jul 23 • Edited

I will do something like this:

import hashlib

url_dict = {}

BASE_URL = "http://localhost/"

def shorten_url(url):
    hash_object = hashlib.md5(url.encode())
    short_code = hash_object.hexdigest()[:6]
    short_url = BASE_URL + short_code
    url_dict[short_code] = url
    return short_url

def get_original_url(short_code):
    return url_dict.get(short_code, "Short URL not found!")

if __name__ == "__main__":
    while True:
        print("1. Shorten a URL")
        print("2. Retrieve original URL")
        print("3. Exit")
        choice = input("Enter your choice: ")

    if choice == '1':
        url = input("Enter the URL to shorten: ")
        short_url = shorten_url(url)
        print(f"Short URL is: {short_url}")
    elif choice == '2':
        short_url = input("Enter the short URL: ")
        short_code = short_url.replace(BASE_URL, "")
        original_url = get_original_url(short_code)
        print(f"Original URL is: {original_url}")
    elif choice == '3':
        break
    else:
        print("Invalid choice, please try again.")

ZeroByteCode • Jul 23

Nice, this is also cool and well-written.

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