```JSON
{
    "message": "Hello World",
    "root_path": "/api/v1"
}
```

### ⚒ `root_path` FastAPI 📱

👐, 🚥 👆 🚫 ✔️ 🌌 🚚 📋 ⏸ 🎛 💖 `--root-path` ⚖️ 🌓, 👆 💪 ⚒ `root_path` 🔢 🕐❔ 🏗 👆 FastAPI 📱:

```Python hl_lines="3"
{!../../docs_src/behind_a_proxy/tutorial002.py!}
```

🚶‍♀️ `root_path` `FastAPI` 🔜 🌓 🚶‍♀️ `--root-path` 📋 ⏸ 🎛 Uvicorn ⚖️ Hypercorn.

### 🔃 `root_path`

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.post("/items/")
async def create_item(item: Item):
    item_dict = item.dict()
    if item.tax:
        price_with_tax = item.price + item.tax
        item_dict.update({"price_with_tax": price_with_tax})

from typing import Union

from fastapi import FastAPI, Path, Query

app = FastAPI()


@app.get("/items/{item_id}")
async def read_items(
    item_id: int = Path(title="The ID of the item to get"),
    q: Union[str, None] = Query(default=None, alias="item-query"),
):
    results = {"item_id": item_id}
    if q:
        results.update({"q": q})

from fastapi import FastAPI, Query

app = FastAPI()


@app.get("/items/")
async def read_items(q: list[str] = Query(default=["foo", "bar"])):
    query_items = {"q": q}

from fastapi import FastAPI, Request

app = FastAPI(root_path="/api/v1")


@app.get("/app")
def read_main(request: Request):

# Templates

Sie können jede gewünschte Template-Engine mit **FastAPI** verwenden.

Eine häufige Wahl ist Jinja2, dasselbe, was auch von Flask und anderen Tools verwendet wird.

Es gibt Werkzeuge zur einfachen Konfiguration, die Sie direkt in Ihrer **FastAPI**-Anwendung verwenden können (bereitgestellt von Starlette).

## Abhängigkeiten installieren

Installieren Sie `jinja2`:

<div class="termy">

```console
$ pip install jinja2

# Templates

Você pode usar qualquer template engine com o **FastAPI**.

Uma escolha comum é o Jinja2, o mesmo usado pelo Flask e outras ferramentas.

Existem utilitários para configurá-lo facilmente que você pode usar diretamente em sua aplicação **FastAPI** (fornecidos pelo Starlette).

## Instalação de dependências

Para instalar o `jinja2`, siga o código abaixo:

<div class="termy">

```console
$ pip install jinja2
```

`FastAPI` jest klasą, która dziedziczy bezpośrednio z `Starlette`.

Oznacza to, że możesz korzystać ze wszystkich funkcjonalności <a href="https://www.starlette.io/" class="external-link" target="_blank">Starlette</a> również w `FastAPI`.

///

### Krok 2: utwórz instancję `FastAPI`

{*../../docs_src/first_steps/tutorial001.py hl[3] *}

Zmienna `app` będzie tutaj "instancją" klasy `FastAPI`.

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, q: str | None = None):
    result = {"item_id": item_id, **item.dict()}
    if q:
        result.update({"q": q})

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}