koxudaxi/datamodel-code-generator 0.55.0

on GitHub

Breaking Changes

Dependency Changes

• Pydantic v1 runtime support removed - Pydantic v2 is now required as a runtime dependency. Users running datamodel-code-generator with Pydantic v1 installed must upgrade to Pydantic v2. The previously deprecated v1 compatibility layer has been completely removed. (#3025)

Default Behavior Changes

• Default output model switched from Pydantic v1 to v2 - Running datamodel-codegen without specifying --output-model-type now generates Pydantic v2 models (pydantic_v2.BaseModel) instead of Pydantic v1 models (pydantic.BaseModel). Users who depend on the previous default behavior must now explicitly specify --output-model-type pydantic.BaseModel to continue generating Pydantic v1 compatible code. (#3029)

Code Generation Changes

• Generated model syntax changed for default output - The default generated code now uses Pydantic v2 syntax including RootModel instead of __root__ fields, native union syntax (str | None) instead of Optional[str], and Pydantic v2 validator/serializer decorators. Existing code that consumes generated models may need updates to work with the new Pydantic v2 output format. (#3029)
• Pydantic v1 output support removed - The pydantic.BaseModel output model type has been completely removed. Generated code now only supports Pydantic v2 patterns including RootModel instead of __root__, model_rebuild() instead of update_forward_refs(), and model_config instead of class Config. Users generating Pydantic v1 models must migrate to v2 output. (#3031)

Custom Template Update Required

• Pydantic v1 templates removed - The following Jinja2 templates have been deleted and users with custom templates extending them must migrate to v2 equivalents:
  • pydantic/BaseModel.jinja2 → use pydantic_v2/BaseModel.jinja2
  • pydantic/BaseModel_root.jinja2 → use pydantic_v2/RootModel.jinja2
  • pydantic/Config.jinja2 → removed (v2 uses model_config dict)
    (#3031)

API/CLI Changes

• --output-model-type pydantic.BaseModel removed - The pydantic.BaseModel value for --output-model-type is no longer valid. Use pydantic_v2.BaseModel instead (now the default). (#3031)
• Pydantic v1 compatibility utilities removed from Python API - The following functions were removed from datamodel_code_generator.util: model_dump(), model_validate(), get_fields_set(), model_copy(). Use Pydantic v2 methods directly (obj.model_dump(), cls.model_validate(), etc.). (#3031)
• datamodel_code_generator.model.pydantic module removed - The entire Pydantic v1 model module including BaseModel, CustomRootType, DataModelField, DataTypeManager, and dump_resolve_reference_action has been removed. Use datamodel_code_generator.model.pydantic_v2 instead. (#3031)
• Pydantic v2 now required at runtime - The minimum pydantic dependency changed from pydantic>=1.5 to pydantic>=2,<3. Users with pydantic v1 installed must upgrade to pydantic v2 before using datamodel-code-generator (#3027)
• Removed internal pydantic compatibility utilities - The following functions/classes were removed from datamodel_code_generator.util: get_pydantic_version(), is_pydantic_v2(), model_validator(), field_validator(), and ConfigDict. Users who imported these internal utilities directly must update their code to use pydantic's native APIs (#3027)
• Removed datamodel_code_generator.pydantic_patch module - The entire pydantic compatibility patching module was removed. Any code importing from this module will fail (#3027)
• Removed packaging dependency - The packaging library is no longer a dependency. Code that relied on it being transitively available should add it explicitly (#3027)

What's Changed

• Extract shared pydantic base module for v2/dataclass/msgspec by @koxudaxi in #3022
• Remove pydantic v1 runtime compat layer by @koxudaxi in #3025
• test: make integration helpers explicit about output model by @koxudaxi in #3028
• feat: switch default output model to pydantic v2 by @koxudaxi in #3029
• test: align v2 parser baselines before v1 output removal by @koxudaxi in #3032
• feat: remove pydantic v1 output support by @koxudaxi in #3031
• docs: remove pydantic v1 references by @koxudaxi in #3030
• Remove pydantic v1 runtime compat shims and update dependencies by @koxudaxi in #3027
• docs: remove final pydantic v1 traces by @koxudaxi in #3036
• Fix all-export generation for hyphenated directories by @an5t in #3033
• Fix exact imports for reused tree-scope models by @koxudaxi in #3042
• fix #3034 and #3035 by introducing ValidatedDefault by @keyz in #3040
• Avoid TYPE_CHECKING imports for Ruff modular output by @koxudaxi in #3043
• Add deprecated decorators for dataclass output by @koxudaxi in #3044
• Fix for #3045 by @ashipilov in #3046
• Refactor generate tests to use assertion helper by @koxudaxi in #3047

New Contributors

• @an5t made their first contribution in #3033
• @keyz made their first contribution in #3040
• @ashipilov made their first contribution in #3046

Full Changelog: 0.54.1...0.55.0