(WIP) high priority / high impact work 🚀

[sydney-runkle]

If you're looking to contribute to pydantic, the fixes / features below are awesome, high-impact and high-demand features! We've also tagged many issues with good first issue that are a bit easier / less involved, so you can start there as well!

Fixes

These should ideally be implemented in the upcoming minor release, though naturally, some take precedence over others.

• Union issues (specifically, serialization choices)
• Revisit unnecessary schema rebuilds sucking up schema build time, ex in Incorrect JSON schema for discriminated unions in nested dataclasses #8628 (@sydney-runkle)
• Url "subclasses" don't enforce constraints #7353

Features

These are high-impact or highly-requested features.

• mode parameter in model_validate logic, Provide a mode parameter in validate_python and model_validate #9009
• Add timezone to tzinfo parsing to pydantic 2.0 #4710 (there are also lots of other tz/zoneinfo/dt/date related issues that could be addressed)
• Allow different serializer to an Annotated type for "python" and "json" mode  #8086
• Improve integration with popular data science libs (numpy, polars, pandas, etc)
• Support custom ordering of string (or other) constraint application, string constraints are applied after pattern #8577
• More support for deprecated fields/models #8922
• Custom validator ordering, Validators execution order #8277
• Allow for serializer functions (model_dump(), model_dump_json()) to raise exceptions in addition to warnings #8978
• Add support for complex numbers Standard complex number not supported!? #8555
• Revisit Allow optional properties to be truely optional #8394
• Add Title Generator to Support Programmatic Titles #4632
• TODO: comb through generic issues

Changes / Important V3 Work

Work that doesn't fit under the umbrella for V2, but is on a high priority list for V3.

High Impact

• Standardize APIs + behavior for alias usage for validation / serialization, More consistent and intuitive alias behavior for validation and serialization #8379
• Reconcile differences between merging configs, Inconsistency: Config is merged for models, but not for dataclasses #7271
• Unexpected validation of nested generic models #7096 (see @dmontagu's comment)
• TODO: comb through generic issues more

Low Impact

• Standardize error messages / types for similar operations, Error message discrepancy #9020
• Migrate highly specific types to pydantic-extra-types, Start migrating dsn types over to pydantic-extra-types #9071

[sydney-runkle]

@NeevCohen @Viicos @ornariece,

If you're looking for anything new to contribute to in the future, here's a fun collection :).

[Youssefares]

Keen to pick up #4710 👀

[sydney-runkle]

@Youssefares, you got it!