What is Urlencode in Python?

When building URLs in Python, you may occasionally need to encode special characters to ensure they transmit properly. For example, spaces need to be converted to %20 and ampersands to %26. Thankfully, Python's urllib module provides simple ways to handle URL encoding.

Why Encode URLs?

URLs only allow certain alphanumeric characters like letters, numbers, and some symbols such as -, _, ., and ~. Everything else, including spaces, foreign letters, and special symbols, need to be encoded.

For example, an URL with spaces like www.example.com/path with spaces would cause issues. Encoding it gives us:

www.example.com/path%20with%20spaces

This ensures special characters transmit safely through networks and servers can properly interpret them.

Python's urllib for URL Encoding

Python's urllib module provides the simple urlencode() function for encoding parameters and values in URLs:

from urllib.parse import urlencode

params = {"name": "John Wick", "category": "Action & Adventure"}
print(urlencode(params))

# name=John+Wick&category=Action+%26+Adventure

We can also manually encode pieces of URLs as needed:

from urllib.parse import quote_plus

url = "http://localhost:8000/movies/" + quote_plus("Science Fiction") 
# http://localhost:8000/movies/Science%20Fiction

The quote_plus() method handles spaces, special characters, and even non-ASCII letters.

When to Encode URLs

Getting in the habit of encoding URLs ensures your applications handle edge cases safely!

I tried to provide some practical examples on why and how to encode URLs in Python, along with tips on specific methods that can help.