# Unterabhängigkeiten

Sie können Abhängigkeiten erstellen, die **Unterabhängigkeiten** haben.

Diese können so **tief** verschachtelt sein, wie nötig.

**FastAPI** kümmert sich darum, sie aufzulösen.

## Erste Abhängigkeit, „Dependable“

Sie könnten eine erste Abhängigkeit („Dependable“) wie folgt erstellen:

//// tab | Python 3.10+

```Python hl_lines="8-9"
{!> ../../docs_src/dependencies/tutorial005_an_py310.py!}
```

////

@REM ----------------------------------------------------------------------------
@REM Licensed to the Apache Software Foundation (ASF) under one
@REM or more contributor license agreements.  See the NOTICE file
@REM distributed with this work for additional information
@REM regarding copyright ownership.  The ASF licenses this file
@REM to you under the Apache License, Version 2.0 (the
@REM "License"); you may not use this file except in compliance

**FastAPI** 🔜 ✊ 👈 🏷, 🏗 🚮 🎻 🔗 & 🔌 ⚫️ ☑ 🥉 🗄.

🖼, 📣 ➕1️⃣ 📨 ⏮️ 👔 📟 `404` & Pydantic 🏷 `Message`, 👆 💪 ✍:

```Python hl_lines="18  22"
{!../../docs_src/additional_responses/tutorial001.py!}
```

/// note

✔️ 🤯 👈 👆 ✔️ 📨 `JSONResponse` 🔗.

///

/// info

`model` 🔑 🚫 🍕 🗄.

**FastAPI** 🔜 ✊ Pydantic 🏷 ⚪️➡️ 📤, 🏗 `JSON Schema`, & 🚮 ⚫️ ☑ 🥉.

☑ 🥉:

Isso significa que você pode enviar apenas os dados que deseja atualizar, deixando o restante intacto.

/// note | Nota

`PATCH` é menos comumente usado e conhecido do que `PUT`.

E muitas equipes usam apenas `PUT`, mesmo para atualizações parciais.

Você é **livre** para usá-los como preferir, **FastAPI** não impõe restrições.

## Attribution

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *

// along with this program.  If not, see <http://www.gnu.org/licenses/>.

package http

import (
	"context"
	"net"
	"time"
)

// CheckPortAvailability - check if given host and port is already in use.
// Note: The check method tries to listen on given port and closes it.
// It is possible to have a disconnected client in this tiny window of time.
func CheckPortAvailability(host, port string, opts TCPOptions) (err error) {

## `StaticFiles` verwenden

* Importieren Sie `StaticFiles`.
* „Mounten“ Sie eine `StaticFiles()`-Instanz in einem bestimmten Pfad.

```Python hl_lines="2  6"
{!../../docs_src/static_files/tutorial001.py!}
```

/// note | "Technische Details"

Sie könnten auch `from starlette.staticfiles import StaticFiles` verwenden.