Why does a return statement in a finally block negates raise in the except block?

Question

In my Python script I would like to catch an exception, perform some cleanup operations, and raise the exception again. Since the cleanup is common for both the success and failure paths, I tried putting it in the finally block. However, when I add a return statement inside the finally block, the raise is negated.

Here is an example (I am using Python 3.6.5):

def test():
    try:
        raise Exception('TEST')
    except:
        raise
    finally:
        print('FINALLY!')
        return ''

if __name__ == '__main__':
    test()
    print('SHOULD NOT REACH THIS LINE!')

Any idea why it is happening?

Answer 1

This is addressed directly in the docs .

On one side:

• An exception could occur during execution of an except or else clause. Again, the exception is re-raised after the finally clause has been executed.

BUT :

• If the finally clause executes a break , continue or return statement, exceptions are not re-raised .