Armin Rigo
Hi Nikolaus,
On Sat, Apr 27, 2013 at 4:39 AM, Nikolaus Rath
wrote: It's indeed very informative, but it doesn't fully address the question because of the _pyio module which certainly can't use any custom C code. Does that mean that when I'm using x = _pyio.BufferedWriter(), I could loose data in the write buffer when the interpreter exits without me calling x.close(), but when using x = io.BufferedWriter(), the buffer is guaranteed to get flushed?
I actually described the behavior of CPython 2 while not realizing that CPython 3 silently dropped this guarantee. (I also never realized that Jython/IronPython don't have the same guarantee; they could, if they implement 'atexit', like we did in PyPy. That's however more acceptable if the platform itself doesn't offer the guarantee.)
Anyway, it's a guarantee that the C offers, so personally I find it reasonable to expect CPython files to offer it too; not offering it is kind of saying that there is a feature of C that is actually present at a higher level than the exact same feature in Python, which looks backward to me.
Additionally, this might be introducing subtle bugs in programs when porting them to Python 3.
However I realize that the two arguments presented above might not be accepted as relevant. (http://bugs.python.org/issue17852)
Thanks for the research! I tried writing a test for this myself, but failed to get the cyclic reference in place properly for it to happen. Seems I'm not the only one who was unaware and/or surprised by he change in behavior. Best, -Nikolaus -- »Time flies like an arrow, fruit flies like a Banana.« PGP fingerprint: 5B93 61F8 4EA2 E279 ABF6 02CF A9AD B7F8 AE4E 425C