The try statement has another optional clause which is intended to define clean-up actions that must be executed under all circumstances. For example:
>>> try: ... raise KeyboardInterrupt ... finally: ... print 'Goodbye, world!' ... Goodbye, world! Traceback (innermost last): File "<stdin>", line 2 KeyboardInterrupt
A finally clause is executed whether or not an exception has occurred in the try clause. When an exception has occurred, it is re-raised after the finally clause is executed. The finally clause is also executed ``on the way out'' when the try statement is left via a break or return statement.
A try statement must either have one or more except clauses or one finally clause, but not both.