Issues

• Add public functions to dataclasses to correctly identify methods and features

  stdlibtopic-dataclassestype-feature
  python/cpython#157314 · Filter by author DavidCEllis opened on Sep 11, 2026
  1

• dataclass tries to generate __init__() even though the class already defines one

  pendingstdlibtopic-dataclassestype-bug
  python/cpython#148941 · Filter by author tonyyuyiding opened on Apr 23, 2026
  6

• Document dataclass field should not be reused

  docspendingtopic-dataclasses
  python/cpython#145369 · Filter by author v01dXYZ opened on Feb 28, 2026
  8

• Better support for descriptors at dataclass creation

  stdlibtopic-dataclassestype-feature
  python/cpython#144749 · Filter by author MrXerios opened on Feb 12, 2026
  2

• Can dataclass ordering avoid tuple wrappers for single field comparisons?

  stdlibtopic-dataclassestype-feature
  python/cpython#144191 · Filter by author rhettinger opened on Jan 23, 2026
  2

  

• Misleading "Not an instance or subtype" error when assigning to property of frozen, slotted dataclass

  stdlibtopic-dataclassestype-bug
  python/cpython#143969 · Filter by author HalfWhitt opened on Jan 17, 2026
  6

  

• Improve documentation on dataclass inheritance

  docstopic-dataclasses
  python/cpython#139497 · Filter by author MarkRotchell opened on Oct 2, 2025
  5

• Improve performance of dataclasses.asdict by caching field names

  performancestdlibtopic-dataclassestype-feature
  python/cpython#138232 · Filter by author eendebakpt opened on Aug 28, 2025

• Dataclasses fields should evaluate their annotations

  pendingstdlibtopic-dataclassestopic-typingtype-feature
  python/cpython#137891 · Filter by author Zaharid opened on Aug 17, 2025
  11

• Inconsistent dataclass order behavior on Python 3.13+

  stdlibtopic-dataclassestype-bug
  python/cpython#137658 · Filter by author gesslerpd opened on Aug 12, 2025
  2

• gh-137658: Fix dataclass order method behaviors to align with the equality semantics

  awaiting reviewtopic-dataclasses
  Unread
  python/cpython#137497·gesslerpd opened Aug 7, 2025 · Updated Aug 23, 2026
  12

• gh-133956 fix bug where ClassVar string annotation in @dataclass caused incorrect __init__ generation

  awaiting changesstaletopic-dataclasses
  Unread
  python/cpython#134073·dzherb opened May 15, 2025 · Updated Apr 24, 2026
  14

  

• dataclasses: Synthetic __init__ method on dataclass has broken ClassVar annotation under some conditions.

  stdlibtopic-dataclassestype-bug
  python/cpython#133956 · Filter by author emcd opened on May 12, 2025
  14

• slotted dataclasses not calling descriptor field __set__

  stdlibtopic-dataclassestype-bug
  python/cpython#132946 · Filter by author thejcannon opened on Apr 25, 2025
  7

  

• Dataclasses erroring when descriptor has mutable default

  stdlibtopic-dataclassestype-bug
  python/cpython#132559 · Filter by author thejcannon opened on Apr 15, 2025
  10

  

• Incorrect __qualname__ in slotted dataclasses in __init_subclass__

  stdlibtopic-dataclassestype-bug
  python/cpython#129915 · Filter by author thejcannon opened on Feb 9, 2025
  1

• dataclasses fail to unpickle when there is an object cycle with a custom __hash__ function

  topic-dataclassestype-bug
  python/cpython#125004 · Filter by author charles-cooper opened on Oct 5, 2024
  2

• pickle.loads will crash with self-references inside a custom hash function

  extension-modulesstdlibtopic-dataclassestype-bug
  python/cpython#124937 · Filter by author charles-cooper opened on Oct 3, 2024
  24

• Improve UX for mocking dataclasses that are problematic to instantiate

  topic-dataclassestype-feature
  python/cpython#124176 · Filter by author ncoghlan opened on Sep 17, 2024
  6

  

• Add examples for repr=... usage in dataclasses.rst

  awaiting reviewdocsskip issueskip newsstaletopic-dataclasses
  Unread
  python/cpython#123118·egorsmth opened Aug 18, 2024 · Updated Apr 18, 2026
  17

• gh-89529: disallow default_factory for fields in dataclasses without __init__

  awaiting reviewstaletopic-dataclasses
  Unread
  python/cpython#123070·picnixz opened Aug 16, 2024 · Updated Apr 25, 2025·Draft
  10

• dataclass overriding a property in the parent class is broken

  stdlibtopic-dataclassestype-bug
  python/cpython#121354 · Filter by author marksandler2 opened on Jul 3, 2024
  11

  

• Processing of fields in dataclasses is inconsistent with MRO

  stdlibtopic-dataclassestype-bug
  python/cpython#108611 · Filter by author eltoder opened on Aug 29, 2023
  3

  

• copy fails on collections.OrderedDict dataclass with required args

  3.113.123.13stdlibtopic-dataclassestype-bug
  python/cpython#105736 · Filter by author ringohoffman opened on Jun 13, 2023
  9

  

• Dataclasses - Improve the performance of _dataclass_{get,set}state

  3.13performancestdlibtopic-dataclassestype-feature
  python/cpython#103032 · Filter by author sobolevn opened on Mar 25, 2023
  7