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[Python-Dev] Remove tempfile.mktemp()

Giampaolo Rodola' g.rodola at gmail.com
Tue Mar 19 12:23:00 EDT 2019 
On Tue, Mar 19, 2019 at 2:06 PM Stéphane Wirtel <stephane at wirtel.be> wrote:
>
> Hi,
>
> Context: raise a warning or remove tempfile.mktemp()
> BPO: https://bugs.python.org/issue36309
>
> Since 2.3, this function is deprecated in the documentation, just in the
> documentation. In the code, there is a commented RuntimeWarning.
> Commented by Guido in 2002, because the warning was too annoying (and I
> understand ;-)).
>
> So, in this BPO, we start to discuss about the future of this function
> and Serhiy proposed to discuss on the Python-dev mailing list.
>
> Question: Should we drop it or add a (Pending)DeprecationWarning?
>
> Suggestion and timeline:
>
> 3.8, we raise a PendingDeprecationWarning
>     * update the code
>     * update the documentation
>     * update the tests
>       (check a PendingDeprecationWarning if sys.version_info == 3.8)
>
> 3.9, we change PendingDeprecationWarning to DeprecationWarning
>       (check DeprecationWarning if sys.version_info == 3.9)
>
> 3.9+, we drop tempfile.mktemp()
>
> What do you suggest?

I concur with others who think this should not be removed. It's used
in different stdlib and third party modules' test suites. I see
tempfile.mktemp() very similar to  test.support.find_unused_port() and
os.path.exists/isfile/isdir functions: they are all subject to race
conditions but still they are widely used and have reason to exist
(practicality beats purity). I suggest turning the doc deprecation
into a note:: or warning::, so that extra visibility is maintained.
Because the use case is legitimate and many fs-related APIs such as
this one are inevitably racy, I lean more towards a note:: rather than
a warning:: though, and we could probably do the same for os.path.is*
functions.

@Sebastian
> If there are valid use cases for mktemp(), I recommend renaming
> it to mkname_unsafe() or something equally obvious.

I'm -1 about adding an alias (there should be one and preferably only
one way to do it). Also mkstemp() and mkdtemp() are somewhat poorly
named IMO, but I wouldn't add an alias for them either.

-- 
Giampaolo - http://grodola.blogspot.com
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