Python Program: Custom Redirect Handling with urllib3

Last update on February 08 2024 12:51:30 (UTC/GMT +8 hours)

Python urllib3 : Exercise-22 with Solution

Write a Python program that implements custom logic to handle redirects based on specific conditions during a request.

Sample Solution:

Python Code :

import urllib3

# Custom redirect handling logic
def handle_redirect(response, redirect_location):
    # Define custom logic to handle redirects based on specific conditions
    if redirect_location.startswith('https://www.example.com'):
        return True
    return False

# Create a custom redirect pool manager
class CustomRedirectPoolManager(urllib3.PoolManager):
    def redirect_request(self, method, url, **kwargs):
        # Override redirect_request method to use custom redirect handling logic
        response = super().request(method, url, **kwargs)
        if response.status == 302 and 'Location' in response.headers:
            redirect_location = response.headers['Location']
            if handle_redirect(response, redirect_location):
                return super().request(method, redirect_location, **kwargs)
        return response

# Create a custom HTTP pool manager with the custom redirect adapter
http = CustomRedirectPoolManager()

# Define the URL for the initial request
initial_url = 'https://www.example.com'

try:
    # Make a GET request
    response = http.request('GET', initial_url)

    # Check if the request was successful (status code 200)
    if response.status == 200:
        print("Request Successful:")
        print(response.data.decode('utf-8'))
    else:
        print(f"Error: Unable to fetch data. Status Code: {response.status}")

except Exception as e:
    print(f"Error: {e}")

Sample Output:

Request Successful:
<!doctype html>
<html>
<head>
    <title>Example Domain</title>

    <meta charset="utf-8" />
    <meta http-equiv="Content-type" content="text/html; charset=utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1" />
    <style type="text/css">
    body {
        background-color: #f0f0f2;
        margin: 0;
        padding: 0;
        font-family: -apple-system, system-ui, BlinkMacSystemFont, "Segoe UI", "Open Sans", "Helvetica Neue", Helvetica, Arial, sans-serif;
        
    }
    div {
        width: 600px;
        margin: 5em auto;
        padding: 2em;
        background-color: #fdfdff;
        border-radius: 0.5em;
        box-shadow: 2px 3px 7px 2px rgba(0,0,0,0.02);
    }
    a:link, a:visited {
        color: #38488f;
        text-decoration: none;
    }
    @media (max-width: 700px) {
        div {
            margin: 0 auto;
            width: auto;
        }
    }
    </style>    
</head>

<body>
<div>
    <h1>Example Domain</h1>
    <p>This domain is for use in illustrative examples in documents. You may use this
    domain in literature without prior coordination or asking for permission.</p>
    <p><a href="https://www.iana.org/domains/example">More information...</a></p>
</div>
</body>
</html>

Explanation:

Here's a brief explanation of the above Python urllib3 library code:

We define a custom redirect pool manager "CustomRedirectPoolManager" by subclassing "urllib3.PoolManager".
We override the "redirect_request()" method to use custom redirect handling logic defined in "handle_redirect".
We define the "handle_redirect()" function to implement custom logic to handle redirects based on specific conditions.
We create a custom HTTP pool manager 'http' using "CustomRedirectPoolManager".
Finally, we make a GET request using the pool manager and handle the response accordingly.

Flowchart:

Python Code Editor :

Have another way to solve this solution? Contribute your code (and comments) through Disqus.

Previous: Python Program: Observing urllib3 Response compression handling.
Next: Python Retry Mechanism with incremental timeouts.