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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
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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
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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 = {}
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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
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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}'
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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
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Main Function to Run the App 

if __name__ == "__main__": app.run(debug=True)
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Step 3: Running the Tool

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

python app.py
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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>
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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)

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stokry profile image
Stokry • • 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.")
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zerobytecode profile image
ZeroByteCode •

Nice, this is also cool and well-written.