FastAPI 生成的 API 文档下拉列表用于显示请求正文的多个示例，但仅显示 1 个示例

Question

我正在关注 FastAPI 教程，特别是有关显示多个示例的部分： https: //fastapi.tiangolo.com/tutorial/schema-extra-example/。

我复制了代码：

from typing import Optional

from fastapi import Body, FastAPI
from pydantic import BaseModel

app = FastAPI()


class Item(BaseModel):
    name: str
    description: Optional[str] = None
    price: float
    tax: Optional[float] = None


@app.put("/items/{item_id}")
async def update_item(
    *,
    item_id: int,
    item: Item = Body(
        ...,
        examples={
            "normal": {
                "summary": "A normal example",
                "description": "A **normal** item works correctly.",
                "value": {
                    "name": "Foo",
                    "description": "A very nice Item",
                    "price": 35.4,
                    "tax": 3.2,
                },
            },
            "converted": {
                "summary": "An example with converted data",
                "description": "FastAPI can convert price `strings` to actual `numbers` automatically",
                "value": {
                    "name": "Bar",
                    "price": "35.4",
                },
            },
            "invalid": {
                "summary": "Invalid data is rejected with an error",
                "value": {
                    "name": "Baz",
                    "price": "thirty five point four",
                },
            },
        },
    ),
):
    results = {"item_id": item_id, "item": item}
    return results

...与页面上显示的完全一样，我使用 Uvicorn 运行它。在我的屏幕上，我没有看到请求正文示例字典中包含 3 个示例的任何下拉菜单。我所看到的只是一个示例值，其中包含字段所需的类型。

为什么会这样，为什么这对我不起作用？

这就是我应该得到的：

但这就是我得到的：

Answer 1

我不确定这是否有帮助： https://github.com/tiangolo/fastapi/pull/1267#issuecomment-762557261 这意味着两件事：

1. 例子需要进去 Item.Config.schema_extra
2. 示例参数必须引用类中的数据

像这样的东西：

class Item(BaseModel):
    name: str
    description: Optional[str] = None
    price: float
    tax: Optional[float] = None

    class Config:
        schema_extra = {
            "examples": {
                "normal": {
                    "summary": "A normal example",
                    "description": "A **normal** item works correctly.",
                    "value": {
                        "name": "Foo",
                        "description": "A very nice Item",
                        "price": 35.4,
                        "tax": 3.2,
                    },
                },
                "converted": {
                    "summary": "An example with converted data",
                    "description": "FastAPI can convert price `strings` to actual `numbers` automatically",
                    "value": {
                        "name": "Bar",
                        "price": "35.4",
                    },
                },
                "invalid": {
                    "summary": "Invalid data is rejected with an error",
                    "value": {
                        "name": "Baz",
                        "price": "thirty five point four",
                    },
                },
            }
        }


@app.put("/items/{item_id}")
async def update_item(
    *,
    item_id: int,
    item: Item = Body(
        None,
        examples=Item.Config.schema_extra["examples"],
    ),
):
    results = {"item_id": item_id, "item": item}
    return results

它帮助了我！