with open('com1', 'r') as f:

[Lawrence D'Oliveiro]

In message <mailman.3438.1239062418.11746.python-list at python.org>, Delaney, 
Timothy (Tim) wrote:

> Lawrence D'Oliveiro wrote:
> 
>> In message <mailman.3332.1238914117.11746.python-list at python.org>,
>> Terry Reedy wrote:
>> 
>>> Lawrence D'Oliveiro wrote:
>>> 
>>>> All Python objects are reference-counted.
>>> 
>>> Nope.  Only in CPython, and even that could change.
>> 
>> Why should it?
> 
> Because Guido has said it might some time in the future.

It's still a matter of efficiency, not correctness.

>>>> Once the file object becomes
>>>> inaccessible, it is automatically closed. Simple.
>>> 
>>> Even in CPython, that would not be true now is the object became
>>> involved in or became a dependent of a reference cycle.
>> 
>> And how exactly would that happen with a file object?
> 
> Create a cycle of objects, and have one of them reference a file object.

Which was not what was happening in the actual situation at hand.