python-attrs/cattrs

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Composable custom class converters for attrs, dataclasses and friends.

Stars: 1.1k
Forks: 159
Open beginner issues: 0
Indexed issues: 80
Avg merge: 12h 21m
Merged PRs (30d): 6

Dominant language: Python
License: MIT
Last GitHub push: Sep 14, 2026
Latest indexed: Sep 20, 2026
Contributing guide: Contributing guide
Code of conduct: Code of conduct
Beginner labels: No beginner labels indexed

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80 open issues indexed

Regression of unstructuring typing.Any based on runtime types Open

Difficulty 3/5 1-2 days Newbie friendliness 35/100

python-attrs/cattrs#320 · 2 comments · Opened Nov 9, 2022
How to serialize (JSON) a type reference? Open

Difficulty 5/5 Over a week Newbie friendliness 20/100

python-attrs/cattrs#315 · 6 comments · Opened Oct 24, 2022
validation options when structuring Open

enhancement

Difficulty 5/5 Over a week Newbie friendliness 25/100

python-attrs/cattrs#307 · 1 comment · Opened Sep 19, 2022
Importing `annotations` from `__future__` causes a StructureHandlerNotFoundError Open

Difficulty 3/5 1-2 days Newbie friendliness 42/100

python-attrs/cattrs#293 · 4 comments · Opened Aug 9, 2022
Unstructuring subclassed built-ins Open

Difficulty 3/5 1-2 days Newbie friendliness 35/100

python-attrs/cattrs#287 · Opened Jul 6, 2022
Allow disambiguating union types by unique literal types Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

python-attrs/cattrs#273 · 9 comments · 2 reactions · Opened Jun 13, 2022
Converter ignores fields from child class when unstructuring (inheritance) Open

Difficulty 4/5 3-5 days Newbie friendliness 38/100

python-attrs/cattrs#272 · 11 comments · 4 reactions · Opened Jun 13, 2022
Weird output while structuring unions with custom disambiguation function Open

Difficulty 3/5 1-2 days Newbie friendliness 35/100

python-attrs/cattrs#267 · 1 comment · Opened May 5, 2022
Default union disambiguation function doesn't work with renamed keys Open

Difficulty 3/5 1-2 days Newbie friendliness 25/100

python-attrs/cattrs#265 · 1 comment · Opened May 3, 2022
Error with adapted_fields when subclassing attr class Open

Difficulty 3/5 1-2 days Newbie friendliness 35/100

python-attrs/cattrs#257 · 3 comments · Opened Apr 22, 2022
structure raises a KeyError when optional attribute is missing Open

Difficulty 3/5 1-2 days Newbie friendliness 48/100

python-attrs/cattrs#249 · 8 comments · Opened Apr 7, 2022
Recent fix to orjson serialization breaks unions Open

Difficulty 2/5 1-3 hours Newbie friendliness 45/100

python-attrs/cattrs#248 · 1 comment · Opened Apr 7, 2022
What's the recommended way of handling child classes? Open

Difficulty 5/5 Over a week Newbie friendliness 25/100

python-attrs/cattrs#246 · Opened Apr 5, 2022
Using make_dict_structure_fn seems to break my other structure hooks Open

Difficulty 4/5 3-5 days Newbie friendliness 45/100

python-attrs/cattrs#243 · 1 comment · Opened Apr 3, 2022
Adding a `make_dict_unstructure_fn` breaks `omit_if_default=True` Open

Difficulty 3/5 1-2 days Newbie friendliness 35/100

python-attrs/cattrs#238 · 2 comments · Opened Mar 24, 2022
kw_only tuple support? Open

Difficulty 3/5 1-2 days Newbie friendliness 52/100

python-attrs/cattrs#234 · 12 comments · Opened Mar 15, 2022
Union disambiguation fails when using `to_camel` structuring/unstructuring hook factories Open

Difficulty 4/5 3-5 days Newbie friendliness 45/100

python-attrs/cattrs#233 · 1 comment · Opened Feb 28, 2022
takes_metadata option for Factory Open

Difficulty 5/5 Over a week Newbie friendliness 35/100

python-attrs/cattrs#232 · 1 comment · 1 reaction · Opened Feb 16, 2022
GenConverter's dict_factory argument has no effect Open

Difficulty 3/5 1-2 days Newbie friendliness 42/100

python-attrs/cattrs#228 · 4 comments · Opened Feb 10, 2022
Register Hooks for Generic Classes Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

python-attrs/cattrs#216 · 4 comments · Opened Feb 2, 2022
cattr.gen.make_dict_structure_fn returns type incompatible with cattr.register_structure_hook causing mypy errors Open

Difficulty 3/5 1-2 days Newbie friendliness 35/100

python-attrs/cattrs#208 · 7 comments · Opened Jan 19, 2022
TypeError when registering ForwardRefs in python 3.10.2 Open

enhancement

Difficulty 3/5 1-2 days Newbie friendliness 64/100

python-attrs/cattrs#206 · 15 comments · 2 reactions · Opened Jan 15, 2022
ForwardRef and GenConverter do not seem to work together Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

python-attrs/cattrs#201 · 15 comments · Opened Dec 21, 2021
Types of nested generic fields are not specific enough Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

python-attrs/cattrs#185 · 2 comments · Opened Nov 15, 2021
Mypy error on structure Open

blocked-upstream

Difficulty 3/5 1-2 days Newbie friendliness 45/100

python-attrs/cattrs#111 · 6 comments · Opened Jan 8, 2021
Using `typing.Any` to register a structure hook for a generic type is not working. Open

Difficulty 3/5 1-2 days Newbie friendliness 35/100

python-attrs/cattrs#87 · 1 comment · Opened May 19, 2020
Structure when input is already partially structured Open

Difficulty 3/5 1-2 days Newbie friendliness 25/100

python-attrs/cattrs#78 · 3 comments · 1 reaction · Opened Dec 3, 2019
Optional fields may break automatic disambiguator Open

Difficulty 3/5 1-2 days Newbie friendliness 55/100

python-attrs/cattrs#70 · 3 reactions · Opened Sep 24, 2019
Most elegant way of doing error-checking and post-processing on `structure`d data? Open

Difficulty 5/5 Over a week Newbie friendliness 25/100

python-attrs/cattrs#58 · Opened Feb 19, 2019
cattrs structure string to List, instead of failing conversion Open

Difficulty 3/5 1-2 days Newbie friendliness 42/100

python-attrs/cattrs#44 · 14 comments · Opened Oct 9, 2018

python-attrs/cattrs

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