{!../../docs_src/first_steps/tutorial001.py!}
```
Декоратор `@app.get("/")` вказує **FastAPI**, що функція нижче, відповідає за обробку запитів, які надходять до неї:

* шлях `/`
* використовуючи <abbr title="an HTTP GET method"><code>get</code> операцію</abbr>

/// info | "`@decorator` Додаткова інформація"

Синтаксис `@something` у Python називається "декоратором".

// DB GORM DB definition
type DB struct {
	*Config
	Error        error
	RowsAffected int64
	Statement    *Statement
	clone        int
}

// Session session config when create session with Session() method
type Session struct {
	DryRun                   bool
	PrepareStmt              bool
	NewDB                    bool
	Initialized              bool
	SkipHooks                bool
	SkipDefaultTransaction   bool

   * this {@code TopKSelector}.
   *
   * <p>The returned list is an unmodifiable copy and will not be affected by further changes to
   * this {@code TopKSelector}. This method returns in O(k log k) time.
   */
  public List<T> topK() {
    @SuppressWarnings("nullness") // safe because we pass sort() a range that contains real Ts
    T[] castBuffer = (T[]) buffer;

pkg bufio, method (*Reader) WriteTo(io.Writer) (int64, error)
pkg bufio, method (*Scanner) Bytes() []uint8
pkg bufio, method (*Scanner) Err() error
pkg bufio, method (*Scanner) Scan() bool
pkg bufio, method (*Scanner) Split(SplitFunc)
pkg bufio, method (*Scanner) Text() string
pkg bufio, method (*Writer) ReadFrom(io.Reader) (int64, error)
pkg bufio, method (ReadWriter) ReadFrom(io.Reader) (int64, error)

     b. any new file in Source Code Form that contains any Covered Software.

1.11. “Patent Claims” of a Contributor

      means any patent claim(s), including without limitation, method, process,
      and apparatus claims, in any patent Licensable by such Contributor that
      would be infringed, but for the grant of the License, by the making,

#### *パスオペレーションデコレータ*を定義

```Python hl_lines="6"
{!../../docs_src/first_steps/tutorial001.py!}
```
`@app.get("/")`は直下の関数が下記のリクエストの処理を担当することを**FastAPI**に伝えます:

* パス `/`
* <abbr title="an HTTP GET method"><code>get</code> オペレーション</abbr>

/// info | "`@decorator` について"

Pythonにおける`@something`シンタックスはデコレータと呼ばれます。

「デコレータ」は関数の上に置きます。かわいらしい装飾的な帽子のようです（この用語の由来はそこにあると思います）。

「デコレータ」は直下の関数を受け取り、それを使って何かを行います。

Hello Wade Wilson
```

</div>

////

## Ler Variáveis de Ambiente no Python

Você também pode criar variáveis de ambiente **fora** do Python, no terminal (ou com qualquer outro método) e depois **lê-las no Python**.

Por exemplo, você poderia ter um arquivo `main.py` com:

```Python hl_lines="3"
import os

name = os.getenv("MY_NAME", "World")
print(f"Hello {name} from Python")
```

///

```Python hl_lines="20-27"
{!> ../../docs_src/schema_extra_example/tutorial003.py!}
```

////

### Beispiel in der Dokumentations-Benutzeroberfläche

Mit jeder der oben genannten Methoden würde es in `/docs` so aussehen:

<img src="/img/tutorial/body-fields/image01.png">

### `Body` mit mehreren `examples`

Sie können natürlich auch mehrere `examples` übergeben:

//// tab | Python 3.10+

* The response `418`. 🍵

But that will only affect that `APIRouter` in our app, not in any other code that uses it.

So, for example, other projects could use the same `APIRouter` with a different authentication method.

### Include a *path operation*

We can also add *path operations* directly to the `FastAPI` app.

Here we do it... just to show that we can 🤷:

```Python hl_lines="21-23" title="app/main.py"

      // before the cancelled future completes, it will synchronously complete both the newFuture
      // from the cancelled operation and its own. This can cause one runnable to queue two tasks,
      // breaking the invariant this method relies on to iteratively run the next task after the
      // previous one completes.
      if (get() == RunningState.CANCELLED) {
        delegate = null;
        sequencer = null;
        return;
      }