Throw From Finally (ARCH2155)

Key python.logging.raise-in-finally · Severity error · Category logging

Raising an exception inside a finally block masks any exception still propagating from the try body. The original failure is lost and replaced by the secondary error from finally.

Incorrect

def write(path, data):
    f = open(path, "w")
    try:
        f.write(data)
    finally:
        f.close()
        raise RuntimeError("cleanup done")

Correct

def write(path, data):
    f = open(path, "w")
    try:
        f.write(data)
    finally:
        f.close()

Fix

Use finally only for cleanup; move any raise into the try/except body.