We see that we are going to need some dependencies used in several places of the application.

So we put them in their own `dependencies` module (`app/dependencies.py`).

We will now use a simple dependency to read a custom `X-Token` header:

{* ../../docs_src/bigger_applications/app_an_py39/dependencies.py hl[3,6:8] title["app/dependencies.py"] *}

/// tip

We are using an invented header to simplify this example.

	set := s.getHashedSet(object)
	return set.PutObject(ctx, bucket, object, data, opts)
}

// GetObjectInfo - reads object metadata from the hashedSet based on the object name.
func (s *erasureSets) GetObjectInfo(ctx context.Context, bucket, object string, opts ObjectOptions) (objInfo ObjectInfo, err error) {
	set := s.getHashedSet(object)

	return &testOneByteReadNoEOF{false, data}
}

// testOneByteReadNoEOF - implements io.Reader which returns 1 byte and nil error, but
// returns io.EOF on the next Read().
type testOneByteReadNoEOF struct {
	eof  bool
	data []byte
}

func (r *testOneByteReadNoEOF) Read(p []byte) (n int, err error) {
	if r.eof {
		return 0, io.EOF
	}
	n = copy(p, r.data)
	r.eof = true
	return n, nil
}

```

</div>

Stellen Sie dann Ihre App bereit:

<div class="termy">

```console
$ fastapi deploy

Deploying to FastAPI Cloud...

✅ Deployment successful!

🐔 Ready the chicken! Your app is ready at https://myapp.fastapicloud.dev
```

</div>

Das war’s! Jetzt können Sie unter dieser URL auf Ihre App zugreifen. ✨

#### Über FastAPI Cloud { #about-fastapi-cloud }

$ $Env:MY_NAME = "Wade Wilson"

// Usá-la com outros programas, como
$ echo "Hello $Env:MY_NAME"

Hello Wade Wilson
```

</div>

////

## Ler Variáveis de Ambiente no Python { #read-env-vars-in-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:

Use the following command to generate a private key with ECDSA:

```sh
openssl ecparam -genkey -name prime256v1 | openssl ec -out private.key
```

A response similar to this one should be displayed:

```
read EC key
writing EC key
```

Alternatively, use the following command to generate a private ECDSA key protected by a password:

```sh

Um **gerenciador de contexto** em Python é algo que você pode usar em uma declaração `with`, por exemplo, `open()` pode ser usado como um gerenciador de contexto:

```Python
with open("file.txt") as file:
    file.read()
```

Em versões mais recentes do Python, há também um **gerenciador de contexto assíncrono**. Você o usaria com `async with`:

```Python
async with lifespan(app):
    await do_stuff()
```

        if (
            isinstance(field_info, params.File)
            and is_bytes_field(field)
            and isinstance(value, UploadFile)
        ):
            value = await value.read()
        elif (
            is_bytes_sequence_field(field)
            and isinstance(field_info, params.File)
            and value_is_sequence(value)
        ):
            # For types

{* ../../docs_src/events/tutorial003.py hl[1,13] *}

파이썬에서 **컨텍스트 매니저**는 `with` 문에서 사용할 수 있는 것입니다. 예를 들어, `open()`은 컨텍스트 매니저로 사용할 수 있습니다:

```Python
with open("file.txt") as file:
    file.read()
```
최근 버전의 파이썬에서는 **비동기 컨텍스트 매니저**도 있습니다. 이를 `async with`와 함께 사용합니다:

```Python
async with lifespan(app):
    await do_stuff()
```

			if o.pool < len(z.serverPools) && o.set < len(z.serverPools[o.pool].sets) {
				o.debugln("Resuming", o)
				entries, err = z.serverPools[o.pool].sets[o.set].streamMetadataParts(ctx, *o)
				entries.reuse = true // We read from stream and are not sharing results.
				if err == nil {
					return entries, nil
				}
			} else {
				err = fmt.Errorf("invalid pool/set")
				o.pool, o.set = 0, 0
			}
		}