Passing Parameters in URLs with Python's urllib

When constructing URL requests in Python, you'll often need to append parameters to the URL to pass additional data to the server. The urllib module provides easy ways to handle this.

For example, say we need to call a URL like:

https://api.example.com/data?category=science&format=json

This passes two parameters, category and format, to the server. Here's how to construct that in Python:

import urllib.parse
import urllib.request

base_url = 'https://api.example.com/data'
params = {'category': 'science', 'format': 'json'}

url = '{}?{}'.format(base_url, urllib.parse.urlencode(params))

data = urllib.request.urlopen(url).read()

The key points:

Some tips:

Overall, urllib makes it straightforward to pass parameters around. The parse module handles all the encoding details for you. And you can use the standard dictionary methods to easily construct, combine, and manage multiple parameters to pass along.