Skip to content

Upgrading pydantic_core 0.42 to 2

Breaking0.42.0 → 2.50.2Breaking9Security1Platform4Deprecated7New121Changed127Fixed376Other146

Full comparisonBack to pydantic_core
Fetching 102 releases from GitHub…101 / 102
BreakingUpgrade verdict

9 breaking changes and 4 platform requirement changes and a security fix.

In plain terms
  • The way fields are defined when calling create_model has changed, which may require updating existing code.
  • You can no longer customize the internal schema generator because its interface may still change.
  • When you provide json_schema_extra as a dict, it is now merged with existing schema extras rather than replacing them.
  • Removes `initial_metadata` from the internal metadata construct.
Must act Top 5 of 21 that need code or config changes

Python requirement changed in 2.47.0: >=3.7 → >=3.10.

Adds typing-extensions >=4.16.0.

Installs 1 package in all (was 0).

What you must change

Breaking9
Reworks the create_model field definitions format.
create_model
2.11.0GitHub ReleaseSummarizedView source
Disallows customization of SchemaGenerator until its interface is more stable.
SchemaGenerator
2.10.0GitHub ReleaseSummarizedView source
Merges dict type json_schema_extra instead of overwriting it.
json_schema_extra
2.9.0GitHub ReleaseSummarizedView source
Removes initial_metadata from the internal metadata construct.
initial_metadata
2.9.0GitHub ReleaseSummarizedView source
Changes the metadata type hint in core schemas from Any to Dict[str, Any] | None.
metadata
2.9.0GitHub ReleaseSummarizedView source
Improves smart union matching logic, changing which union member matches in some cases.
smartUnion
2.8.0GitHub ReleaseSummarizedView source
Uses positional-only self in BaseModel constructor, so no field name can conflict with it.
BaseModel
2.6.0GitHub ReleaseSummarizedView source
Makes @validate_call return a function instead of a custom descriptor, fixing binding with inheritance and adding self/cls to validation errors.
@validate_call
2.6.0GitHub ReleaseSummarizedView source
Replaces ultra_strict with a new smart union implementation, significantly changing how unions are validated.
ultra_strict
2.5.0GitHub ReleaseSummarizedView source
Security1
Fixes a regular expression denial of service issue by limiting whitespaces.
2.4.0GitHub ReleaseSummarizedView source
Platform4
Drops support for Python 3.9 and adds support for Python 3.15.
2.14.0GitHub ReleaseSummarizedView source
Removes Python 3.8 support.
2.11.0GitHub ReleaseSummarizedView source
Adds support for Python 3.13.
2.8.0GitHub ReleaseSummarizedView source
Drops Python 3.7, and PyPy 3.7 and 3.8.
2.6.0GitHub ReleaseSummarizedView source

Deprecations to plan for

Deprecated7
Raises a deprecation warning when a field is annotated as final with a default value.
2.11.0GitHub ReleaseSummarizedView source
Deprecates accessing model_fields and model_computed_fields on instances.
model_fieldsmodel_computed_fields
2.11.0GitHub ReleaseSummarizedView source
Recommends against using Ellipsis (...) with Field.
FieldEllipsis
2.10.0GitHub ReleaseSummarizedView source
Deprecates passing a dict to the Examples class.
Examples
2.9.0GitHub ReleaseSummarizedView source
Deprecates the update_json_schema internal function.
update_json_schema
2.7.0GitHub ReleaseSummarizedView source
Marks Extra as deprecated.
Extra
2.4.0GitHub ReleaseSummarizedView source
Deprecates Field.include.
Field.include
2.2.0GitHub ReleaseSummarizedView source