all Python 3OOPfunction

__exit__

context manager

The method run on leaving a with block: always called, even on an exception, and given its type, value and traceback.

Syntax

def __exit__(self, exc_type, exc_value, traceback): ...

On a normal exit all three arguments are None. Returning a true value suppresses the exception and execution continues after the with; the default is to return None or False, otherwise errors vanish silently. __exit__ is what guarantees the file gets closed and the lock released.

Examples

class Guard:
    def __enter__(self):
        return self
    def __exit__(self, exc_type, exc, tb):
        print('exit:', exc_type.__name__ if exc_type else None)
        return exc_type is ZeroDivisionError  # подавить только деление на ноль
with Guard():
    pass  # → exit: None
with Guard():
    1 / 0  # → exit: ZeroDivisionError
print('продолжаем')  # → продолжаем — исключение подавлено

See also

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