On Jul 3, 5:34 am, Jack Diederich <jackd...@gmail.com> wrote: > On Thu, Jul 2, 2009 at 2:36 PM, Carl Banks<pavlovevide...@gmail.com> wrote: > > Warning: objects with a __del__ attribute prevent reference cycle > > detection, which can potentially lead to memory (and resource) leaks. > > So you must be careful to avoid creating reference loops with that > > object. > > WARNING-er: As Carl points out, adding a __del__ method actually makes > it /less/ likely that your object will be cleaned up.
No I wasn't pointing that out, and I don't really agree with it. (You can't really say it is "more likely" or "less likely" without considering the skill and patience of the programmer, and there are many programmers who are up to the task.) __del__ can succeed with care, and if you are willing to give up a certain amount of flexibility and portability I don't recommend going that way. For one thing RAII isn't quite so wonderful in Python's dynamic environment as it is in C++'s static universe, and people seem to expect more from it than they get. Second, relying on implementation-dependent behavior is not a good thing and can set you up for problems later, something few people expect to happen to them but it does more often than they think. (Search comp.lang.python for a thread started by Warren DeLano for an example of someone who got bit hard by such a change he should have seen coming.) But still I leave that for them to risk for themselves. [snip] > If you care enough about a resource to write a __del__ method > you care enough to clean it up explicitly. 'with' blocks are very > nice for that. The OP already said with blocks won't suffice since the resources are long-lived objects that aren't limited to a single scope. Carl Banks -- http://mail.python.org/mailman/listinfo/python-list
