FastAPI：如何将任意属性dict映射到pydantic模型以让swagger显示细节

Question

我有一个 FastAPI 项目，其中一个endpoint如下所示：

@app.post(
    response=SomePydanticModel() # how to compose SomePydanticModel here???
)
def my_end_point():
    response = {
        "ZOOQ-700Z71": [
            {"product_id": "prod_001", "product_name": "Product 001", "quantity": 10},
            {"product_id": "prod_002", "product_name": "Product 002", "quantity": 20},
            {"product_id": "prod_004", "product_name": "Product 004", "quantity": 30},
        ],
        "0071-ZOGKNQ": [
            {"product_id": "prod_001", "product_name": "Product 001", "quantity": 10},
            {"product_id": "prod_003", "product_name": "Product 003", "quantity": 7},
            {"product_id": "prod_008", "product_name": "Product 008", "quantity": 2},
        ],
        "0071-Z0GKQ7": [
            {"product_id": "prod_002", "product_name": "Product 002", "quantity": 12},
            {"product_id": "prod_007", "product_name": "Product 007", "quantity": 6},
        ],
        "ZZOQ-ZXOCT9": [
            {"product_id": "prod_004", "product_name": "Product 004", "quantity": 100},
        ],
        "2007-ZCKOZR": [
            {"product_id": "prod_004", "product_name": "Product 004", "quantity": 30},
            {"product_id": "prod_005", "product_name": "Product 005", "quantity": 20},
        ],
    }

如您所见，我的响应是任意属性dict，其格式为xxxx-xxxxxx的属性是采购订单ID。我如何编写SomePydanticModel来表示我的响应？因此，我希望大摇大摆地展示我的回应。

Answer 1

您可以使用将 Dict 作为根类型的模型，将键作为具有正则表达式模式的约束字符串结构。

例如：

from typing import Dict, List

from fastapi import FastAPI
from pydantic import BaseModel, constr

app = FastAPI()


class Product(BaseModel):
    product_id: str
    product_name: str
    quantity: int


ConStrType = constr(regex=r'^[A-Z0-9]{4}-[A-Z0-9]{6}$')
ProductDict = Dict[ConStrType, List[Product]]


class ProductModel(BaseModel):
    __root__: ProductDict



@app.post("/products", response_model=ProductModel)
def my_end_point():
    return {
        "ZOOQ-700Z71": [
            {"product_id": "prod_001", "product_name": "Product 001", "quantity": 10},
            {"product_id": "prod_002", "product_name": "Product 002", "quantity": 20},
            {"product_id": "prod_004", "product_name": "Product 004", "quantity": 30},
        ],
        "0071-ZOGKNQ": [
            {"product_id": "prod_001", "product_name": "Product 001", "quantity": 10},
            {"product_id": "prod_003", "product_name": "Product 003", "quantity": 7},
            {"product_id": "prod_008", "product_name": "Product 008", "quantity": 2},
        ],
        "0071-Z0GKQ7": [
            {"product_id": "prod_002", "product_name": "Product 002", "quantity": 12},
            {"product_id": "prod_007", "product_name": "Product 007", "quantity": 6},
        ],
        "ZZOQ-ZXOCT9": [
            {"product_id": "prod_004", "product_name": "Product 004", "quantity": 100},
        ],
        "2007-ZCKOZR": [
            {"product_id": "prod_004", "product_name": "Product 004", "quantity": 30},
            {"product_id": "prod_005", "product_name": "Product 005", "quantity": 20},
        ],
    }