fastApi笔记06-请求体-多个参数

多个请求体参数 from fastapi import FastAPI, Path, Query from pydantic import BaseModel app = FastAPI() class Item(BaseModel): name: str description: str | None = None price: float tax: float | None = None class User(BaseModel): username: str full_name: str | None = None @app.put("/items") async def update_item(item: Item, user: User): results = {"item": item, "user": user} return results

 当函数有多个请求实体（多个 Pydantic 模型参数），将使用参数名称作为请求体中的键（字段名称），并期望一个类似于以下内容的请求体

{ "item": { "name": "Foo", "description": "The pretender", "price": 42.0, "tax": 3.2 }, "user": { "username": "dave", "full_name": "Dave Grohl" } }

请求体中的单一值

 假如为了拓展先前的模型，除了user和item之外，在请求体中增加一个字段importance，需要使用Body来声明，不然会被当做查询参数

from fastapi import FastAPI, Body from pydantic import BaseModel app = FastAPI() class Item(BaseModel): name: str description: str | None = None price: float tax: float | None = None class User(BaseModel): username: str full_name: str | None = None @app.put("/items") async def update_item(item: Item, user: User, importance: int = Body()): results = {"item": item, "user": user, "importance": importance} return results { "item": { "name": "Foo", "description": "The pretender", "price": 42.0, "tax": 3.2 }, "user": { "username": "dave", "full_name": "Dave Grohl" }, "importance": 5 }

嵌入单个请求体实参

 假如只有一个来自的模型Item，如果你希望它期望一个拥有 item 键并在值中包含模型内容的 JSON，就像在声明额外的请求体参数时所做的那样。比如下面这样的。

{ "item": { "name": "Foo", "description": "The pretender", "price": 42.0, "tax": 3.2 } }

而不是这样的。

{ "name": "Foo", "description": "The pretender", "price": 42.0, "tax": 3.2 }

则可以使用一个特殊的 Body 参数 embed

from typing import Annotated from fastapi import Body, FastAPI from pydantic import BaseModel app = FastAPI() class Item(BaseModel): name: str description: str | None = None price: float tax: float | None = None @app.put("/items/{item_id}") async def update_item(item_id: int, item: Annotated[Item, Body(embed=True)]): results = {"item_id": item_id, "item": item} return results

 声明模型属性

和使用Query，Path，Body在路径操作函数中声明参数校验和元数据的方式相同，可以使Pydantic 的Field在模型内部进行声明校验和元数据

from typing import Annotated from fastapi import Body, FastAPI from pydantic import BaseModel, Field app = FastAPI() class Item(BaseModel): name: str description: str | None = Field( default=None, title="The description of the item", max_length=300 ) price: float = Field(gt=0, description="The price must be greater than zero") tax: float | None = None @app.put("/items/{item_id}") async def update_item(item_id: int, item: Annotated[Item, Body(embed=True)]): results = {"item_id": item_id, "item": item} return results