Python HTTP Request with Network Exception Handling Example

Last update on February 03 2024 13:06:05 (UTC/GMT +8 hours)

Python urllib3 : Exercise-9 with Solution

Write a Python program that implements error handling for network-related exceptions that might occur during a request.

Sample Solution:

Python Code :

import urllib3

def make_http_request(url):
    try:
        # Create a PoolManager instance for managing HTTP connections
        with urllib3.PoolManager() as http:
            # Make an HTTP GET request
            response = http.request('GET', 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 urllib3.exceptions.RequestError as e:
        print(f"Network Error: {e}")
    except Exception as e:
        print(f"Error: {e}")

if __name__ == "__main__":
    # Define the URL for the HTTP request
    target_url = 'https://www.example.com'

    # Make the HTTP request with error handling
    make_http_request(target_url)

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>

Note:
The warning we are seeing is an "InsecureRequestWarning" from the "urllib3" library, indicating that you are making an HTTPS request without SSL/TLS verification. This warning is raised because disabling SSL/TLS verification can expose your application to potential security risks, such as man-in-the-middle attacks.

Explanation:

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

Import Library:

urllib3: Used for handling HTTP requests.

Define Function:

make_http_request(url): Makes an HTTP GET request to the specified URL with error handling for network-related exceptions.

Make HTTP Request:

Use urllib3.PoolManager() to manage HTTP connections.
Inside the with block, make an HTTP GET request using http.request('GET', url).

Check Response Status:

Check if the response status is 200 (OK).
If successful, print the response content.

Error Handling:

Use a try-except block to catch potential "urllib3" network-related exceptions (specifically, urllib3.exceptions.RequestError).
If a network error occurs, print an appropriate error message.
Additionally, catch the general "Exception" to handle unexpected errors and print an error message.

Run the Function:

Calls the make_http_request() function with the target URL to perform the HTTP request.

Flowchart:

Python Code Editor :

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