Or it might be the case that you just prefer to take other courses because they adapt better to your learning style.

Some course providers ✨ [**sponsor FastAPI**](../help-fastapi.md#sponsor-the-author){.internal-link target=_blank} ✨, this ensures the continued and healthy **development** of FastAPI and its **ecosystem**.

Wenn Sie die `async`-Methoden verwenden, führt **FastAPI** die Datei-Methoden in einem <abbr title="Mehrere unabhängige Kindprozesse">Threadpool</abbr> aus und erwartet sie.

///

/// note | "Technische Details zu Starlette"

**FastAPI**s `UploadFile` erbt direkt von **Starlette**s `UploadFile`, fügt aber ein paar notwendige Teile hinzu, um es kompatibel mit **Pydantic** und anderen Teilen von FastAPI zu machen.

///

/// check | "检查"

**FastAPI** 使用 Python 类型声明实现了数据校验。

注意，上面的错误清晰地指出了未通过校验的具体原因。

这在开发调试与 API 交互的代码时非常有用。

///

## 查看文档

访问 <a href="http://127.0.0.1:8000/docs" class="external-link" target="_blank">http://127.0.0.1:8000/docs</a>，查看自动生成的 API 文档：

<img src="/img/tutorial/path-params/image01.png">

/// check | "检查"

还是使用 Python 类型声明，**FastAPI** 提供了（集成 Swagger UI 的）API 文档。

注意，路径参数的类型是整数。

## Webhooks mit **FastAPI** und OpenAPI dokumentieren

/// note | "Technical Details"

You could also use `from starlette import status`.

**FastAPI** provides the same `starlette.status` as `fastapi.status` just as a convenience for you, the developer. But it comes directly from Starlette.

///

## Changing the default

✋️ 👈 🔜 🕴 ✔ 🎯 🆎 📻, 🚫 🌐 👈 🔌 🎓: 🍪, ✔ 🎚 💖 📚 ⚙️ ⏮️ 📨 🤝, ♒️.

, 🌐 👷 ☑, ⚫️ 👻 ✔ 🎯 ✔ 🇨🇳.

## ⚙️ `CORSMiddleware`

👆 💪 🔗 ⚫️ 👆 **FastAPI** 🈸 ⚙️ `CORSMiddleware`.

* 🗄 `CORSMiddleware`.
* ✍ 📇 ✔ 🇨🇳 (🎻).
* 🚮 ⚫️ "🛠️" 👆 **FastAPI** 🈸.

👆 💪 ✔ 🚥 👆 👩‍💻 ✔:

* 🎓 (✔ 🎚, 🍪, ♒️).
* 🎯 🇺🇸🔍 👩‍🔬 (`POST`, `PUT`) ⚖️ 🌐 👫 ⏮️ 🃏 `"*"`.
* 🎯 🇺🇸🔍 🎚 ⚖️ 🌐 👫 ⏮️ 🃏 `"*"`.

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}")

from fastapi import Depends, FastAPI, Header, HTTPException
from typing_extensions import Annotated

app = FastAPI()


async def verify_token(x_token: Annotated[str, Header()]):
    if x_token != "fake-super-secret-token":
        raise HTTPException(status_code=400, detail="X-Token header invalid")


async def verify_key(x_key: Annotated[str, Header()]):
    if x_key != "fake-super-secret-key":

from typing import Annotated

from fastapi import Depends, FastAPI, Header, HTTPException

app = FastAPI()


async def verify_token(x_token: Annotated[str, Header()]):
    if x_token != "fake-super-secret-token":
        raise HTTPException(status_code=400, detail="X-Token header invalid")


async def verify_key(x_key: Annotated[str, Header()]):
    if x_key != "fake-super-secret-key":

from typing import List, Union

from fastapi import FastAPI
from pydantic import BaseModel

app = FastAPI()


class Item(BaseModel):
    name: str
    description: Union[str, None] = None
    price: float
    tax: float = 10.5
    tags: List[str] = []


items = {
    "foo": {"name": "Foo", "price": 50.2},
    "bar": {"name": "Bar", "description": "The bartenders", "price": 62, "tax": 20.2},