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| -rw-r--r-- | Doc/tutorial/errors.rst | 31 | ||||
| -rw-r--r-- | Misc/ACKS | 1 |
2 files changed, 23 insertions, 9 deletions
diff --git a/Doc/tutorial/errors.rst b/Doc/tutorial/errors.rst index e9a63e4..75a4925 100644 --- a/Doc/tutorial/errors.rst +++ b/Doc/tutorial/errors.rst @@ -388,15 +388,28 @@ example:: File "<stdin>", line 2, in <module> KeyboardInterrupt -A *finally clause* is always executed before leaving the :keyword:`try` -statement, whether an exception has occurred or not. When an exception has -occurred in the :keyword:`!try` clause and has not been handled by an -:keyword:`except` clause (or it has occurred in an :keyword:`!except` or -:keyword:`!else` clause), it is re-raised after the :keyword:`finally` clause has -been executed. The :keyword:`!finally` clause is also executed "on the way out" -when any other clause of the :keyword:`!try` statement is left via a -:keyword:`break`, :keyword:`continue` or :keyword:`return` statement. A more -complicated example:: +If a :keyword:`finally` clause is present, the :keyword:`finally` clause will execute as the last task before the :keyword:`try` statement completes. The :keyword:`finally` clause runs whether or not the :keyword:`try` statement produces an exception. The following points discuss more complex cases when an exception occurs: + +* If an exception occurs during execution of the :keyword:`!try` clause, the exception may be handled by an :keyword:`except` clause. In all cases, the exception is re-raised after the :keyword:`!finally` clause has been executed. + +* An exception could occur during execution of an :keyword:`!except` or :keyword:`!else` clause. Again, the exception is re-raised after the :keyword:`!finally` clause has been executed. + +* If the :keyword:`!try` statement reaches a :keyword:`break`, :keyword:`continue` or :keyword:`return` statement, the :keyword:`finally` clause will execute just prior to the :keyword:`break`, :keyword:`continue` or :keyword:`return` statement's execution. + +* If a :keyword:`finally` clause includes a :keyword:`return` statement, the :keyword:`finally` clause's :keyword:`return` statement will execute before, and instead of, the :keyword:`return` statement in a :keyword:`try` clause. + +For example:: + + >>> def bool_return(): -> bool: + ... try: + ... return True + ... finally: + ... return False + ... + >>> bool_return() + False + +A more complicated example:: >>> def divide(x, y): ... try: @@ -58,6 +58,7 @@ Jon Anglin Michele Angrisano Ankur Ankan Heidi Annexstad +David Antonini Ramchandra Apte Éric Araujo Alexandru Ardelean |