[Tutor] finally

[bob gailer]

On 6/23/2010 7:36 PM, Christopher King wrote:
>     In a try except clause, you can end with finally block. I know it 
> runs after the try and except blocks regardless of the outcome, but 
> why use it. Couldn't you just put the code after the try and except 
> block without using a finally block. Does the finally command do 
> something I don't know about. Does it make your program more 
> understandable in some way?

Did you read the manual?

"If finally <#finally> is present, it specifies a 'cleanup' handler. The 
try <#try> clause is executed, including any except <#except> and else 
<#else> clauses. If an exception occurs in any of the clauses and is not 
handled, the exception is temporarily saved. The finally <#finally> 
clause is executed. If there is a saved exception, it is re-raised at 
the end of the finally <#finally> clause. If the finally <#finally> 
clause raises another exception or executes a return 
<simple_stmts.html#return> or break <simple_stmts.html#break> statement, 
the saved exception is lost. The exception information is not available 
to the program during execution of the finally <#finally> clause.

"When a return <simple_stmts.html#return>, break 
<simple_stmts.html#break> or continue <simple_stmts.html#continue> 
statement is executed in the try <#try> suite of a try <#try>...finally 
<#finally> statement, the finally <#finally> clause is also executed 'on 
the way out.' A continue <simple_stmts.html#continue> statement is 
illegal in the finally <#finally> clause. (The reason is a problem with 
the current implementation --- this restriction may be lifted in the 
future)."

-- 
Bob Gailer
919-636-4239
Chapel Hill NC

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