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Thu Oct 17 19:28:11 CEST 2013 · https://mail.python.org/pipermail/python-dev/2013-October/129663.html

On 10/17/2013 9:06 AM, Barry Warsaw wrote:
> There's a fundamental conceptual shift here that's worth exploring more, and
> which I think was first identified by RDM.
>
> Until now, context managers were at their heart (at least IMHO) about managing
> "resources".  A general resource might be an open file, or it might be a
> database transaction, or even the current working directory.  Context managers
> (as expressed elegantly by the `with` statement) are used to ensure that a
> resource acquired for some limited operation is - to Python's best ability -
> "released" at the end of that operation, no matter what happens.  E.g. the
> file is closed even if there's a write error, or the current working directory
> is restored to its original location.

The conceptual shift exists, as you two have pointed out. But that is 
mostly because Structured programming and OO have created sufficient 
conceptual idioms that people have forgotten that all of these idioms 
are to avoid bare gotos. The real purpose of all such constructs is to 
manage the instruction pointer, and context managers, while useful for 
managing "resources" in the abstract, are truly about managing the 
control flow -- hopefully in understandable ways.
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[Python-Dev] On suppress()'s trail blazing (was Re: cpython: Rename contextlib.ignored() to contextlib.ignore())