Timeout and Error Handling in Requests

When working with web requests, it is essential to manage timeouts and handle potential errors to make your application robust and reliable. The Requests library in Python provides mechanisms to set timeouts and catch exceptions effectively.

Setting Timeouts for Requests

Setting a timeout ensures that your program does not hang indefinitely while waiting for a response from the server. Use the timeout parameter to specify a maximum wait time for the request.

Example: Setting a Timeout

import requests
 
url = "https://httpbin.org/delay/5"  # Simulates a delay of 5 seconds
 
try:
    response = requests.get(url, timeout=3)  # Timeout set to 3 seconds
    print("Response received:", response.text)
except requests.exceptions.Timeout:
    print("The request timed out!")

Output (if timeout occurs)

The request timed out!

Handling Exceptions

Requests can raise several exceptions, depending on the situation. Catching these exceptions ensures your program handles errors gracefully.

Common Exceptions

requests.exceptions.RequestException: Base class for all exceptions in Requests.
requests.exceptions.Timeout: Raised when a request times out.
requests.exceptions.ConnectionError: Raised for network-related errors.
requests.exceptions.HTTPError: Raised for HTTP-specific errors, such as 4xx or 5xx responses.

Example: Catching Specific Exceptions

url = "https://example.com/nonexistent"
 
try:
    response = requests.get(url, timeout=5)
    response.raise_for_status()  # Raises HTTPError for bad responses (4xx and 5xx)
    print("Response received:", response.text)
except requests.exceptions.Timeout:
    print("The request timed out!")
except requests.exceptions.ConnectionError:
    print("A connection error occurred!")
except requests.exceptions.HTTPError as err:
    print(f"HTTP error occurred: {err}")
except requests.exceptions.RequestException as err:
    print(f"An error occurred: {err}")

Using `raise_for_status()` for HTTP Errors

The raise_for_status() method raises an HTTPError if the HTTP response contains a 4xx or 5xx status code.

Example: Handling HTTP Errors

url = "https://httpbin.org/status/404"  # Simulates a 404 error
 
try:
    response = requests.get(url)
    response.raise_for_status()
    print("Response received:", response.text)
except requests.exceptions.HTTPError as err:
    print(f"HTTP error occurred: {err}")

Try It Yourself

Problem 1: Timeout Handling

Send a GET request to https://httpbin.org/delay/10 with a timeout of 5 seconds. Handle the timeout exception gracefully.

Show Solution

import requests
 
url = "https://httpbin.org/delay/10"
 
try:
    response = requests.get(url, timeout=5)
    print("Response received:", response.text)
except requests.exceptions.Timeout:
    print("The request timed out!")

Problem 2: Catching HTTP Errors

Send a GET request to https://httpbin.org/status/500 and handle the HTTPError exception.