Building a URL Shortener with Variable Rules in Python
Introduction:
In this blog post, we will discuss how to build a URL shortener with variable rules in Python. We will create a web application that allows users to specify custom URLs and associate them with either a redirect URL or a file. By using variable routes and JSON data storage, we can efficiently handle different combinations of URLs and provide the appropriate response to the users.
Code Example: Below is an example code snippet demonstrating how to implement the functionality described above using Flask, a popular web framework for Python.
from flask import Flask, redirect
import json
import os
app = Flask(__name__)
# Load URLs from urls.json file
def load_urls():
if os.path.exists('urls.json'):
with open('urls.json') as urls_file:
return json.load(urls_file)
return {}
# Define a route with a variable rule
@app.route('/<string:code>')
def redirect_to_url(code):
urls = load_urls()
if code in urls:
if 'url' in urls[code]:
return redirect(urls[code]['url'])
elif 'file' in urls[code]:
# Code to display the file associated with the code
return f"Displaying file: {urls[code]['file']}"
return "URL not found"
if __name__ == '__main__':
app.run()
Explanation:
- The
load_urlsfunction is responsible for loading the URLs and their associated data from theurls.jsonfile. - The
/<string:code>route defines a variable rule where any string after the first slash in the URL is captured ascode. - Inside the route function
redirect_to_url, we check if the providedcodeexists in the loaded URLs data. - If the
codematches a key in the URLs dictionary, we check if it is associated with a URL or a file. If it’s a URL, we redirect the user to that URL. If it’s a file, we display a message indicating the file. - If the
codedoes not match any URLs in the data, we return a message indicating that the URL was not found.
Conclusion:
In this blog post, we have explored how to create a URL shortener with variable rules in Python using Flask. By utilizing variable routes and JSON data storage, we have implemented a simple yet effective solution for handling custom URLs and their associated actions. This approach can be extended and enhanced further to suit more complex requirements in real-world applications.