gh-148242: Full restoration of the historical behavior of defaultdict, without losing thread safety - #148880
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Changaco wants to merge 13 commits into
Open
gh-148242: Full restoration of the historical behavior of defaultdict, without losing thread safety#148880Changaco wants to merge 13 commits into
defaultdict, without losing thread safety#148880Changaco wants to merge 13 commits into
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Partial revert of pythonGH-142668 (a043407).
Changaco
requested review from
markshannon,
methane and
rhettinger
as code owners
April 22, 2026 16:59
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All commit authors signed the Contributor License Agreement. |
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This PR is stale because it has been open for 90 days with no activity. |
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This is one of the possible solutions to #148242. It has the advantage of being transparent to users since it doesn't break any existing code. The downside is that it doesn't completely fix the unsafe design of the
defaultdictclass.Changes to the private C API (not strictly necessary, could be dropped):
dict_unhashable_typefunction becomes the exposed_Py_dict_unhashable_type_PyCriticalSection_WarnIfNotHeldfunction is createdMinor fix of the
defaultdict.__missing__docstring.Alternatives:
defaultdict.__missing__methoddefaultdict.__missing__method while keeping support for custom__missing__methods (gh-148242: Partial restoration of the historical behavior ofdefaultdict, without losing thread safety #148881)__missing__methods entirely📚 Documentation preview 📚: https://cpython-previews--148880.org.readthedocs.build/