Path: csiph.com!fu-berlin.de!uni-berlin.de!not-for-mail
From: Oscar Benjamin <oscar.j.benjamin@gmail.com>
Newsgroups: comp.lang.python
Subject: Re: Make a unique filesystem path, without creating the file
Date: Tue, 16 Feb 2016 08:35:40 +0000
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References: <85egce6a8a.fsf@benfinney.id.au> <20160215230539.GA42677@cskk.homeip.net> <851t8d42rt.fsf@benfinney.id.au>
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On 16 Feb 2016 05:57, "Ben Finney" <ben+python@benfinney.id.au> wrote:
>
> Cameron Simpson <cs@zip.com.au> writes:
>
> > I've been watching this for a few days, and am struggling to
> > understand your use case.
>
> Yes, you're not alone. This surprises me, which is why I'm persisting.
>
> > Can you elaborate with a concrete example and its purpose which would
> > work with a mktemp-ish official function?
>
> An example::
>
>     import io
>     import tempfile
>     names =3D tempfile._get_candidate_names()
>
>     def test_frobnicates_configured_spungfile():
>         """ =E2=80=98foo=E2=80=99 should frobnicate the configured spungf=
ile. """
>
>         fake_file_path =3D os.path.join(tempfile.gettempdir(), names.next=
())
>         fake_file =3D io.BytesIO("Lorem ipsum, dolor sit
amet".encode("utf-8"))
>
>         patch_builtins_open(
>                 when_accessing_path=3Dfake_file_path,
>                 provide_file=3Dfake_file)
>
>         system_under_test.config.spungfile_path =3D fake_file_path
>         system_under_test.foo()
>         assert_correctly_frobnicated(fake_file)

If you're going to patch open to return a fake file when asked to open
fake_file_path why do you care whether there is a real file of that name?

--
Oscar