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Super Model for Pydantic

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A lightweight extension of Pydantic's BaseModel that adds generic type introspection and retrieval of fields annotated with typing.Annotated.

Installation

Install with pip

pip install pydantic-super-model

Features

  • Generic support
  • Able to retrieve field(s) with a specific Annotation

Generic Example

from pydantic_super_model import SuperModel

class UserWithType[T](SuperModel):
    """User model with a generic type."""

    id: T
    name: str

user = UserWithType[int](id=1, name="John Doe")

user_type = user.get_type() # int

Annotation Example

from typing import Annotated
from pydantic_super_model import SuperModel


class _PrimaryKeyAnnotation:
    pass

PrimaryKey = Annotated[int, _PrimaryKeyAnnotation]

class UserWithAnnotation(SuperModel):
    """User model with an Annotation for a field."""

    id: PrimaryKey
    name: str

user = UserWithAnnotation(id=1, name="John Doe")

annotations = user.get_annotated_fields(PrimaryKey)
# {"id": 1}

Documentation

Get Annotated Fields

SuperModel.get_annotated_fields(*annotations) returns a dict of field names to values for fields whose type hints carry any of the provided annotations (either the Annotated[...] alias or the meta annotation type).

It includes falsy values (like 0 or an empty string) and includes None only when the field was explicitly provided. Unset default None values are omitted.

from typing import Annotated
from pydantic_super_model import SuperModel

class _PrimaryKey:
    pass

PrimaryKey = Annotated[int, _PrimaryKey]

class User(SuperModel):
    id: PrimaryKey
    name: str

u = User(id=1, name="Jane")

assert u.get_annotated_fields(PrimaryKey) == {"id": 1}

Explicit None vs. unset default:

class UserOptional(SuperModel):
    id: PrimaryKey | None = None
    name: str

# Unset default None is omitted
assert not UserOptional(name="A").get_annotated_fields(PrimaryKey)

# Explicit None is included
assert UserOptional(id=None, name="B").get_annotated_fields(PrimaryKey) == {"id": None}

FieldNotImplemented Annotation

You can use the FieldNotImplemented annotation to mark fields that should not be set. An example use case are experimental fields that you intend on implementing later.

from typing import Annotated
from pydantic_super_model import SuperModel, FieldNotImplemented

class Experimental(SuperModel):
    test_field: Annotated[int, FieldNotImplemented]
    name: str

# Raises NotImplementedError because the field is provided
Experimental(test_field=1, name="x")

# Optional + unset default is allowed
class ExperimentalOptional(SuperModel):
    test_field: Annotated[int | None, FieldNotImplemented] = None
    name: str

ExperimentalOptional(name="ok")  # ok (field is unset)

Generics

Use get_type() to retrieve the concrete generic type parameter supplied at instantiation time.

from pydantic_super_model import SuperModel

class UserWithType[T](SuperModel):
    id: T
    name: str

u = UserWithType[int](id=1, name="Charlie")

assert u.get_type() is int

Run Tests

  • Install with the dev extra: pip install pydantic-super-model[dev]
  • Run tests with pytest .

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Pydantic BaseModel supercharged with essential methods

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