How do I handle exceptions in concurrent futures?

How do I handle exceptions in concurrent futures?

You can handle exceptions in concurrent futures by using the as_completed method or by checking the result of each future.

Can you give me an example of that?

Sure! Here's a simple example:

from concurrent.futures import ThreadPoolExecutor, as_completed

def task(n):
    if n == 2:
        raise ValueError('An error occurred!')
    return n * 2

with ThreadPoolExecutor() as executor:
    futures = {executor.submit(task, i): i for i in range(5)}
    for future in as_completed(futures):
        try:
            result = future.result()
            print(f'Result: {result}')
        except Exception as e:
            print(f'Error: {e}')

What happens if I don't handle exceptions?

If you don't handle exceptions, the program will terminate, and you'll lose any results from the other tasks that completed successfully.

Is there a way to log exceptions instead of just printing them?

Yes, you can use the logging module to log exceptions instead of printing them. Just replace the print statement with a logging call.