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TST: fix a logic flaw in a pytest fixture#19567

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neutrinoceros:tst/threading-switchfreq
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TST: fix a logic flaw in a pytest fixture#19567
neutrinoceros wants to merge 1 commit into
astropy:mainfrom
neutrinoceros:tst/threading-switchfreq

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@neutrinoceros neutrinoceros commented Apr 11, 2026

Description

Technically this is a fix to a logic flaw (we should not update the switching frequency unconditionally), but not worth backporting; it's merely theoritical.

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Thank you for your contribution to Astropy! 🌌 This checklist is meant to remind the package maintainers who will review this pull request of some common things to look for.

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@neutrinoceros neutrinoceros marked this pull request as ready for review April 11, 2026 17:48
Comment thread astropy/conftest.py
"""
old = sys.getswitchinterval()
sys.setswitchinterval(1e-6)
sys.setswitchinterval(min(old, 1e-6))
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If old is indeed smaller than 1e-6, shouldn't this be a no-op instead?

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That is exactly what I meant to write. Is there an inconsistency I'm not seeing ?

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I mean if min(old, 1e-6) is still old, why call sys.setswitchinterval(...) at all?

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Just a style preference.

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The (admittedly small) gain is that I don't need to refer to the variable storing the new interval more than once, so there's 0 chance of two occurrences drifting apart.

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What about this? 😅

    old = sys.getswitchinterval()
    new = 1e-6
    if old > new:
        sys.setswitchinterval(new)
    yield
    if old > new:
        sys.setswitchinterval(old)

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4 references to old , as many to new, and 5 LOCs where one 2 suffice is just worse in my honest opinon.

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Well, the stated goal is to fix flaw, not to minimize LOC 😆

@astrofrog do you have second opinion? 🙏

@neutrinoceros neutrinoceros modified the milestones: v8.0.0, v8.1.0 Apr 29, 2026
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in any case, this is just fixing a hypothetical defect that to my knowledge has no actual impact in existing systems, so I'm moving it to 8.1.0 to ever so slightly reduce 8.0.0's backlog

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