Overview
Pydantic 2.12, released on October 7, 2025, supports Python 3.14, adds exclude_if, and polymorphic serialization.
Main Features
exclude_if and polymorphic serialization
exclude_if allows conditionally excluding fields during serialization. Polymorphic serialization automatically handles subclasses with a discriminator.
python
from pydantic import BaseModel, Field
class User(BaseModel):
name: str
password: str = Field(exclude_if=lambda v: True)
age: int = Field(exclude_if=lambda v: v < 0)
u = User(name='Alice', password='secret', age=30)
print(u.model_dump())
# {'name': 'Alice', 'age': 30}