Python - pydantic（2）嵌套模型

class User(BaseModel):
    id: int  # 必填字段
    name: str = "小菠萝"  # 有默认值，选填字段
    signup_ts: Optional[datetime] = None
    friends: List[int] = []  # 列表中元素是 int 类型，或可以直接转成 int 的类型
# 关键字参数
user = User(id="1",
            name="大菠萝",
            signup_ts="2021-09-16 12:22")
print(user.dict())
# 字典解包传参
data = {
    "id": "2",
    "name": "大大的菠萝",
    "friends": [1, 2, 3]
}
user = User(**data)
print(user.dict())
# 输出结果
{'id': 1, 'name': '大菠萝', 'signup_ts': datetime.datetime(2021, 9, 16, 12, 22), 'friends': []}
{'id': 2, 'name': '大大的菠萝', 'signup_ts': None, 'friends': [1, 2, 3]}

from typing import List
from pydantic import BaseModel
class Foo(BaseModel):
    count: int
    size: float = None
class Bar(BaseModel):
    apple = 'x'
    banana = 'y'
class Spam(BaseModel):
    foo: Foo
    bars: List[Bar]
f = Foo(count=2)
b = Bar()
s = Spam(foo=f, bars=[b])
print(s.dict())
# 输出结果
{'bars': [{'apple': 'x', 'banana': 'y'}], 'foo': {'count': 2, 'size': None}}