from fastapi import FastAPI
from fastapi.routing import APIRoute
from pydantic import BaseModel


def custom_generate_unique_id(route: APIRoute):
    return f"{route.tags[0]}-{route.name}"


app = FastAPI(generate_unique_id_function=custom_generate_unique_id)


class Item(BaseModel):
    name: str
    price: float


class ResponseMessage(BaseModel):
    message: str


class User(BaseModel):
    username: str

You could also use `from starlette.testclient import TestClient`.

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

///

/// tip

🔜, 🔠 📨 🔽 ➡ `/v1/` 🔜 🍵 🏺 🈸.

& 🎂 🔜 🍵 **FastAPI**.

🚥 👆 🏃 ⚫️ ⏮️ Uvicorn &amp; 🚶 <a href="http://localhost:8000/v1/" class="external-link" target="_blank">http://localhost:8000/v1/</a> 👆 🔜 👀 📨 ⚪️➡️ 🏺:

```txt
Hello, World from Flask!
```

&amp; 🚥 👆 🚶 <a href="http://localhost:8000/v2" class="external-link" target="_blank">http://localhost:8000/v2</a> 👆 🔜 👀 📨 ⚪️➡️ FastAPI:

```JSON
{
    "message": "Hello World"

from typing import Optional

from dirty_equals import IsDict
from fastapi import FastAPI
from fastapi.testclient import TestClient

app = FastAPI()


@app.get(
    "/",
    openapi_extra={
        "parameters": [
            {
                "required": False,
                "schema": {"title": "Extra Param 1"},
                "name": "extra_param_1",
                "in": "query",
            },
            {

from typing import Optional

from fastapi import Depends, FastAPI, Query, status
from fastapi.testclient import TestClient

app = FastAPI()


def _get_client_key(client_id: str = Query(...)) -> str:
    return f"{client_id}_key"


def _get_client_tag(client_id: Optional[str] = Query(None)) -> Optional[str]:
    if client_id is None:
        return None
    return f"{client_id}_tag"


@app.get("/foo")
def foo_handler(

Wenn Sie mit **FastAPI** arbeiten, müssen Sie sich darüber keine Sorgen machen, da diese „erste“ Funktion Ihre *Pfadoperation-Funktion* sein wird und FastAPI weiß, was zu tun ist.

Wenn Sie jedoch `async` / `await` ohne FastAPI verwenden möchten, können Sie dies auch tun.

### Schreiben Sie Ihren eigenen asynchronen Code

Örneğin `pip install python-multipart`.

///

## `Form` Sınıfını Projenize Dahil Edin

`Form` sınıfını `fastapi`'den projenize dahil edin:

//// tab | Python 3.9+

```Python hl_lines="3"
{!> ../../docs_src/request_forms/tutorial001_an_py39.py!}
```

////

//// tab | Python 3.8+

```Python hl_lines="1"

This would allow you to **re-use the model** in **multiple places** and also to declare validations and metadata for all the parameters at once. 😎

/// note

This is supported since FastAPI version `0.115.0`. 🤓

///

## Header Parameters with a Pydantic Model

Declare the **header parameters** that you need in a **Pydantic model**, and then declare the parameter as `Header`:

//// tab | Python 3.10+

from typing import Union

from fastapi import FastAPI
from fastapi.encoders import jsonable_encoder
from pydantic import BaseModel

app = FastAPI()


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


items = {
    "foo": {"name": "Foo", "price": 50.2},

⭕ 📨, 📨 `Response` 🔗 🌅 ⏩ 🌘 🛬 📖.

👉 ↩️ 🔢, FastAPI 🔜 ✔ 🔠 🏬 🔘 & ⚒ 💭 ⚫️ 🎻 ⏮️ 🎻, ⚙️ 🎏 [🎻 🔗 🔢](../tutorial/encoder.md){.internal-link target=_blank} 🔬 🔰. 👉 ⚫️❔ ✔ 👆 📨 **❌ 🎚**, 🖼 💽 🏷.

✋️ 🚥 👆 🎯 👈 🎚 👈 👆 🛬 **🎻 ⏮️ 🎻**, 👆 💪 🚶‍♀️ ⚫️ 🔗 📨 🎓 & ❎ ➕ 🌥 👈 FastAPI 🔜 ✔️ 🚶‍♀️ 👆 📨 🎚 🔘 `jsonable_encoder` ⏭ 🚶‍♀️ ⚫️ 📨 🎓.

```Python hl_lines="2  7"
{!../../docs_src/custom_response/tutorial001b.py!}