///

`RequestValidationError` 是 Pydantic 的 <a href="https://docs.pydantic.dev/latest/concepts/models/#error-handling" class="external-link" target="_blank">`ValidationError`</a> 的子类。

**FastAPI** 调用的就是 `RequestValidationError` 类，因此，如果在 `response_model` 中使用 Pydantic 模型，且数据有错误时，在日志中就会看到这个错误。

但客户端或用户看不到这个错误。反之，客户端接收到的是 HTTP 状态码为 `500` 的「内部服务器错误」。

这是因为在*响应*或代码（不是在客户端的请求里）中出现的 Pydantic `ValidationError` 是代码的 bug。

def test_openapi_schema():
    """
    Test that example overrides work:

    * pydantic model schema_extra is included
    * Body(example={}) overrides schema_extra in pydantic model
    * Body(examples{}) overrides Body(example={}) and schema_extra in pydantic model
    """
    app = create_app()
    client = TestClient(app)
    response = client.get("/openapi.json")

from typing import Union

from fastapi import FastAPI
from pydantic.v1 import BaseModel


class Item(BaseModel):
    name: str
    description: Union[str, None] = None
    size: float


app = FastAPI()


@app.post("/items/")
async def create_item(item: Item) -> Item:

from pydantic.v1 import BaseSettings


class Settings(BaseSettings):
    app_name: str = "Awesome API"
    admin_email: str
    items_per_user: int = 50

    class Config:

from fastapi import FastAPI
from pydantic import BaseModel


class Item(BaseModel):
    name: str
    description: str | None = None
    price: float
    tax: float | None = None


app = FastAPI()


@app.put("/items/{item_id}")
async def update_item(item_id: int, item: Item):

///

## Verwendet von **FastAPI** { #used-by-fastapi }

### <a href="https://docs.pydantic.dev/" class="external-link" target="_blank">Pydantic</a> { #pydantic }

Pydantic ist eine Bibliothek zum Definieren von Datenvalidierung, Serialisierung und Dokumentation (unter Verwendung von JSON Schema) basierend auf Python-Typhinweisen.

Если вы хотите обезопасить свой API, есть несколько более эффективных вещей, которые можно сделать, например:

* Убедитесь, что у вас чётко определены Pydantic-модели для тел запросов и ответов.
* Настройте необходимые разрешения и роли с помощью зависимостей.
* Никогда не храните пароли в открытом виде, только хэши паролей.

from typing import Annotated

from fastapi import FastAPI, Header
from pydantic import BaseModel

app = FastAPI()


class CommonHeaders(BaseModel):
    host: str
    save_data: bool
    if_modified_since: str | None = None
    traceparent: str | None = None
    x_tag: list[str] = []


@app.get("/items/")
async def read_items(headers: Annotated[CommonHeaders, Header()]):

from fastapi import FastAPI, status
from pydantic import BaseModel

app = FastAPI()


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


@app.post("/items/", response_model=Item, status_code=status.HTTP_201_CREATED)
async def create_item(item: Item):

from fastapi import FastAPI
from pydantic import BaseModel, HttpUrl

app = FastAPI()


class Image(BaseModel):
    url: HttpUrl
    name: str


@app.post("/images/multiple/")
async def create_multiple_images(images: list[Image]):