Overview

Pydantic 1.10, released on July 16, 2022, introduces strict mode and model_rebuild for dynamic model reconstruction.

Main Features

Strict mode

Strict mode disables automatic type coercion, rejecting values that don't exactly match the declared type.

python 
from pydantic import BaseModel, validator

class User(BaseModel):
    name: str
    age: int

    class Config:
        strict = True

# OK
u = User(name='Alice', age=30)
print(u)

# In strict mode, age='30' would raise an error
# because str -> int coercion is disabled

model_rebuild

The model_rebuild method reconstructs a model after modifying its references, useful for models with circular dependencies.

python 
from __future__ import annotations
from pydantic import BaseModel
from typing import Optional, List

class Node(BaseModel):
    value: int
    children: List[Node] = []

Node.model_rebuild()  # resolve references

tree = Node(value=1, children=[
    Node(value=2),
    Node(value=3, children=[Node(value=4)]),
])
print(tree.json())

Sources