* **Corrotinas**

## Código assíncrono { #asynchronous-code }

Código assíncrono apenas significa que a linguagem 💬 tem um jeito de dizer para o computador / programa 🤖 que em certo ponto do código, ele 🤖 terá que esperar *algo* finalizar em outro lugar. Vamos dizer que esse *algo* seja chamado "arquivo lento" 📝.

Então, durante esse tempo, o computador pode ir e fazer outro trabalho, enquanto o "arquivo lento" 📝 termina.

// Copyright 2013 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package tar_test

import (
	"archive/tar"
	"bytes"
	"fmt"
	"io"
	"log"
	"os"
)

func Example_minimal() {
	// Create and add some files to the archive.
	var buf bytes.Buffer
	tw := tar.NewWriter(&buf)
	var files = []struct {
		Name, Body string
	}{

             Importing from <font color="#75507B">/home/user/code/</font><font color="#AD7FA8">awesomeapp</font>

   <span style="background-color:#007166"><font color="#D3D7CF"> module </font></span>  🐍 main.py

     <span style="background-color:#007166"><font color="#D3D7CF"> code </font></span>  Importing the FastAPI app object from the module with the
             following code:

			return 0, err
		}
		return 0, fmt.Errorf("no exit code (in %q)", string(b))
	}

	// Parse the exit code.
	code, err := strconv.Atoi(string(match[1]))
	if err != nil {
		// Something is malformed. Flush.
		if _, err := f.w.Write(b); err != nil {
			return 0, err
		}
		return 0, fmt.Errorf("bad exit code: %v (in %q)", err, string(b))
	}
	return code, nil
}

          <description>
            <![CDATA[
            A repository id or an expression matching one or many repository ids to mirror, e.g.,
            <code>central</code> or <code>*,!repo1</code>.
            <code>*</code>, <code>external:*</code> and <code>external:http:*</code> (since Maven 3.8.0) have
            a special meaning: see <a href="/guides/mini/guide-mirror-settings.html">Mirror Settings</a> guide.
            ]]>

FROM python:3.9

WORKDIR /code

COPY ./requirements.txt /code/requirements.txt

RUN pip install --no-cache-dir --upgrade -r /code/requirements.txt

# (1)!
COPY ./main.py /code/

# (2)!
CMD ["fastapi", "run", "main.py", "--port", "80"]
```

1. Copia el archivo `main.py` directamente al directorio `/code` (sin ningún directorio `./app`).

	case s_IFDIR:
		mode |= fs.ModeDir
	case s_IFIFO:
		mode |= fs.ModeNamedPipe
	case s_IFLNK:
		mode |= fs.ModeSymlink
	case s_IFREG:
		// nothing to do
	case s_IFSOCK:
		mode |= fs.ModeSocket
	}
	if m&s_ISGID != 0 {
		mode |= fs.ModeSetgid
	}
	if m&s_ISUID != 0 {
		mode |= fs.ModeSetuid
	}
	if m&s_ISVTX != 0 {
		mode |= fs.ModeSticky
	}
	return mode

<font color="#3465A4">INFO    </font> Resolved absolute path <font color="#75507B">/home/user/code/awesomeapp/</font><font color="#AD7FA8">main.py</font>
<font color="#3465A4">INFO    </font> Searching for package file structure from directories with <font color="#3465A4">__init__.py</font> files
<font color="#3465A4">INFO    </font> Importing from <font color="#75507B">/home/user/code/</font><font color="#AD7FA8">awesomeapp</font>

You can define logic (code) that should be executed before the application **starts up**. This means that this code will be executed **once**, **before** the application **starts receiving requests**.

The same way, you can define logic (code) that should be executed when the application is **shutting down**. In this case, this code will be executed **once**, **after** having handled possibly **many requests**.

# Eventos de lifespan { #lifespan-events }

Você pode definir a lógica (código) que deve ser executada antes da aplicação **inicializar**. Isso significa que esse código será executado **uma vez**, **antes** de a aplicação **começar a receber requisições**.