Properly Encode URLs in Python Requests with urllib

When sending HTTP requests in Python, it's important to properly encode the URL to handle special characters correctly. The urllib module provides easy ways to encode URLs for use in Python scripts.

Why URL Encoding Matters

URLs may contain special characters like spaces, slashes, question marks, etc. Most HTTP servers can't properly handle these raw URLs. Encoding the URL converts these special characters into a format web servers can process.

For example, an unencoded space character would look like my%20url when encoded. Encoding allows that URL to be transmitted properly.

Encoding URLs in Python with urllib

The urllib.parse.quote() method handles URL encoding in Python:

from urllib.parse import quote

url = 'https://www.mywebsite.com/search?value=python tips'
encoded_url = quote(url)
print(encoded_url)

# Prints: https%3A%2F%2Fwww.mywebsite.com%2Fsearch%3Fvalue%3Dpython%20tips

The quote() function handles encoding the special characters like ?, = and spaces properly.

You can also use quote_plus() to encode spaces as + instead of %20 which is compatible with some web servers.

Encoding URL Components

You may only want to encode a component of the URL like the query string parameters:

from urllib.parse import quote_plus

base = 'https://www.example.com?' 
params = 'q=python+learning&type=tips'

encoded_params = quote_plus(params) 

url = base + encoded_params

print(url)
# https://www.example.com?q=python%2Blearning&type=tips

This allows encoding only the user-supplied parts of the URL.

Handling Encoding Errors

If an invalid character is encountered during encoding, a UnicodeEncodeError may be raised. You can handle this by specifying an errors policy:

quote(value, safe='/', errors='ignore')

The ignore policy will skip encoding characters that generate errors. Other policies like replace are also available.

Properly encoding URLs is crucial for transmitting requests properly. Python's urllib makes the process straightforward. Encode full URLs, components, handle errors - and you're ready to call URLs reliably.