RFC: Proposal: Deterministic Object Destruction

[Ooomzay]

On Saturday, 3 March 2018 23:52:34 UTC, Steven D'Aprano  wrote:
> I know that laziness and hubris are programmer virtues, but there is 
> still such a thing as *too much laziness*. RAII works in C++ where 
> instances are allocated in the stack, but even there, if you have an 
> especially long-lived function, your resources won't be closed promptly. 
> In Python terms:
> 
> def function():
>     x = open_resource()
>     process(x)
>     # and we're done with x now, but too lazy to explicitly close it
>     sleep(10000) # Simulate some more work. Lots of work.
>     return
>     # and finally x is closed (2.8 hours after you finished using it)
> 
> The answer in C++ is "well don't do that then". The answer is Python is, 
> "don't be so lazy, just use a with statement".

The answer in C++ would be to say "don't be so lazy just put the x 
manipulation in a function or sub-block". The answer with Python + this PEP would be "don't be so lazy just put the x manipulation in a function or explicitly del x" ...no new syntax.

> If you want deterministic closing of resources, with statements are the 
> way to do it.
> 
> def function():
>     with open_resource() as x:
>         process(x)
>     # and x is guaranteed to be closed

What a palava!