finally clause

Оновлено: 24.04.2023

If finally is present, it specifies a „cleanup“ handler. The try clause is executed, including any except and else clauses. If an exception occurs in any of the clauses and is not handled, the exception is temporarily saved. The finally clause is executed. If there is a saved exception it is re-raised at the end of the finally clause. If the finally clause raises another exception, the saved exception is set as the context of the new exception. If the finally clause executes a return, break or continue statement, the saved exception is discarded:

>>> def f():
...     try:
...         1/0
...     finally:
...         return 42
...
>>> f()
42

The exception information is not available to the program during execution of the finally clause.

When a return, break or continue statement is executed in the try suite of a try…finally statement, the finally clause is also executed „on the way out.“

The return value of a function is determined by the last return statement executed. Since the finally clause always executes, a return statement executed in the finally clause will always be the last one executed:

>>> def foo():
...     try:
...         return 'try'
...     finally:
...         return 'finally'
...
>>> foo()
'finally'

python