**FastAPI** provides a convenience tool to structure your application while keeping all the flexibility.

/// info

If you come from Flask, this would be the equivalent of Flask's Blueprints.

///

## An example file structure { #an-example-file-structure }

Let's say you have a file structure like this:

```
.
├── app

            public void write(final InputStream ins) throws IOException {
                assertEquals("""
                        <?xml version="1.0" encoding="UTF-8"?>
                        <OpenSearchDescription xmlns="http://a9.com/-/spec/opensearch/1.1/">
                          <ShortName>Fess</ShortName>
                          <Description>Full Text Search for Your Documents.</Description>
                          <Tags>Full Text Search</Tags>

import org.mockito.Mock;
import org.mockito.MockitoAnnotations;

import jcifs.Configuration;
import jcifs.RuntimeCIFSException;
import jcifs.internal.SMBProtocolDecodingException;
import jcifs.internal.smb1.com.SmbComNTCreateAndXResponse;
import jcifs.internal.util.SMBUtil;

/**
 * Test class for AndXServerMessageBlock
 */
class AndXServerMessageBlockTest {

    @Mock
    private Configuration mockConfig;

    @Mock
    private SmbTransport transport;

    @Mock
    private InetAddress localAddr;

    private static final int DEFAULT_PORT = 445;
    private static final String TEST_HOST = "test.server.com";
    private static final int LOCAL_PORT = 12345;

    @BeforeEach
    void setUp() {
        // Common setup for all tests
    }

    @Nested
    @DisplayName("GetSmbTransport Methods")

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

package cmd

import (
	"fmt"
	"sync"
	"sync/atomic"
	"time"

	"github.com/rcrowley/go-metrics"
)

//go:generate msgp -file $GOFILE

const (
	// beta is the weight used to calculate exponential moving average
	beta = 0.1 // Number of averages considered = 1/(1-beta)
)

/*!
  * Bootstrap v5.3.0 (https://getbootstrap.com/)
  * Copyright 2011-2023 The Bootstrap Authors (https://github.com/twbs/bootstrap/graphs/contributors)
  * Licensed under MIT (https://github.com/twbs/bootstrap/blob/main/LICENSE)
  */

Because `Annotated` can have more than one metadata annotation, you could now even use the same function with other tools, like <a href="https://typer.tiangolo.com/" class="external-link" target="_blank">Typer</a>. 🚀

## Add more validations { #add-more-validations }

You can also add a parameter `min_length`:

Here we are declaring a `UserIn` model, it will contain a plaintext password:

{* ../../docs_src/response_model/tutorial002_py310.py hl[7,9] *}

/// info

To use `EmailStr`, first install <a href="https://github.com/JoshData/python-email-validator" class="external-link" target="_blank">`email-validator`</a>.

      random: Random?,
      pingIntervalMillis: Int = 0,
      responseHeaders: Headers? = headersOf(),
      webSocketCloseTimeout: Long = RealWebSocket.CANCEL_AFTER_CLOSE_MILLIS,
    ) {
      val url = "http://example.com/websocket"
      val response =
        Response
          .Builder()
          .code(101)
          .message("OK")
          .request(Request.Builder().url(url).build())
          .headers(responseHeaders!!)

## 📨 🎏 🔢 💽

📥 👥 📣 `UserIn` 🏷, ⚫️ 🔜 🔌 🔢 🔐:

{* ../../docs_src/response_model/tutorial002.py hl[9,11] *}

/// info

⚙️ `EmailStr`, 🥇 ❎ <a href="https://github.com/JoshData/python-email-validator" class="external-link" target="_blank">`email-validator`</a>.

🤶 Ⓜ. `pip install email-validator`
⚖️ `pip install pydantic[email]`.

///

&amp; 👥 ⚙️ 👉 🏷 📣 👆 🔢 &amp; 🎏 🏷 📣 👆 🔢: