Destructors and exceptions

Dominic nomail at nospam.no
Tue Jun 8 10:38:45 CEST 2004


David Turner wrote:
> Hi
> 
> 
>>If you want to force the issue, give your class a close method, as with
>>file objects, and call it explicitly.  Then code in try:finally:, which is
>>designed for this purpose.
>>try:
>>   process
>>finally:
>>   cleanup
>>
> 
> 
> That's a great shame.  "Finally" is of course susceptible to the
> "forgetful programmer" syndrom.  It also pollutes the code with what I
> consider to be implementation details -- for example, the fact that a
> file must be closed is a characteristic of the file object, and only
> accidentally relevant to the _use_ of files.  Python would be a much
> stronger language if it could guarantee deterministic destruction of
Well, there had been some discussion before. You can
wrap the open/close actions in a closure and write
something like with_file_do(myFunction).

Ciao,
  Dominic

> at least those objects which have a __del__ method.  Can anyone point
> out any technical reasons why such a feature should not be included in
> the language?
> 
> At any rate, I wonder if there is an another solution to the problem
> of resource management.  Perhaps something along the lines of Ruby
> closures?  Any suggestions?  There has to be something more elegant
> (and safer!) than "finally".
> 
> Regards
> David Turner



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