[Python-checkins] r85987 - python/branches/py3k/Lib/test/test_os.py

Nick Coghlan ncoghlan at gmail.com
Mon Nov 1 17:30:09 CET 2010

On Tue, Nov 2, 2010 at 2:10 AM, Hirokazu Yamamoto
<ocean-city at m2.ccsnet.ne.jp> wrote:
> Does this really cause resource warning? I think os.popen instance
> won't be into traceback because it's not declared as variable. So I
> suppose it will be deleted by reference count == 0 even when exception
> occurs.

Any time __del__ has to close the resource triggers ResourceWarning,
regardless of whether that is due to the cyclic garbage collector or
the refcount naturally falling to zero. In the past dealing with this
was clumsy, so it made sense to rely on CPython's refcounting to do
the work. However, we have better tools for deterministic resource
management now (in the form of context managers), so these updates
help make the standard library and its test suite more suitable for
use with non-refcounting Python implementations (such as PyPy, Jython
and IronPython).


Nick Coghlan   |   ncoghlan at gmail.com   |   Brisbane, Australia

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