So:

```Python
q: Union[str, None] = Query(default=None)
```

...makes the parameter optional, with a default value of `None`, the same as:

```Python
q: Union[str, None] = None
```

And in Python 3.10 and above:

```Python
q: str | None = Query(default=None)
```

...makes the parameter optional, with a default value of `None`, the same as:

```Python

In the same way, you can use `finally` to make sure the exit steps are executed, no matter if there was an exception or not.

```Python hl_lines="3  5"
{!../../docs_src/dependencies/tutorial007.py!}
```

## Sub-dependencies with `yield`

You can have sub-dependencies and "trees" of sub-dependencies of any size and shape, and any or all of them can use `yield`.

					testCase.prefix, "marker:", testCase.marker, "delimiter:",
					testCase.delimiter, "maxkeys:", testCase.maxKeys)

				resultV, err = obj.ListObjectVersions(context.Background(), testCase.bucketName,
					testCase.prefix, testCase.marker, "", testCase.delimiter, testCase.maxKeys)
			} else {
				t.Log("ListObjects, bucket:", testCase.bucketName, "prefix:",

			// since Linux 4.11.
			_ = syscall.SetsockoptInt(fd, syscall.IPPROTO_TCP, unix.TCP_FASTOPEN_CONNECT, 1)

			// Enable TCP quick ACK, John Nagle says
			// "Set TCP_QUICKACK. If you find a case where that makes things worse, let me know."
			_ = syscall.SetsockoptInt(fd, syscall.IPPROTO_TCP, unix.TCP_QUICKACK, 1)

			/// Enable keep-alive
			{
				_ = unix.SetsockoptInt(fd, unix.SOL_SOCKET, unix.SO_KEEPALIVE, 1)

```Python
{"id": id}
```

For example, with an ID of `42`, this would render:

```html
Item ID: 42
```

### Template `url_for` Arguments

You can also use `url_for()` inside of the template, it takes as arguments the same arguments that would be used by your *path operation function*.

So, the section with:

{% raw %}

```jinja
<a href="{{ url_for('read_item', id=id) }}">
```

{% endraw %}

MinIO server allows WORM for specific objects or by configuring a bucket with default object lock configuration that applies default retention mode and retention duration to all objects. This makes objects in the bucket immutable i.e. delete of the version are not allowed until an expiry specified in the bucket's object lock configuration or object retention.

    build-all.

    Takes an optional LANG argument with the name of the language to serve, by default
    en.
    """
    # Enable line numbers during local development to make it easier to highlight
    if lang is None:
        lang = "en"
    lang_path: Path = docs_path / lang
    # Enable line numbers during local development to make it easier to highlight

				break
			}

			if !rule.Expiration.IsDaysNull() {
				// Specifying the Days tag will automatically perform ExpiredObjectDeleteMarker cleanup
				// once delete markers are old enough to satisfy the age criteria.
				// https://docs.aws.amazon.com/AmazonS3/latest/userguide/lifecycle-configuration-examples.html

* Generate <a href="https://json-schema.org" class="external-link" target="_blank">JSON Schema</a> definitions for your model, you can also use them anywhere else you like if it makes sense for your project.
* Those schemas will be part of the generated OpenAPI schema, and used by the automatic documentation <abbr title="User Interfaces">UIs</abbr>.

## Automatic docs

		{Name: "file.go", Data: []byte("hello"), Mode: 0644},
		{Name: "subfolder/another.go", Data: []byte("world"), Mode: 0644},
		// Notably missing here is the "subfolder" directory. This makes sure even
		// if we don't have a subfolder directory listed.
	}
	err := w.AddFS(writeTestsToFS(tests))
	if err != nil {
		t.Fatal(err)
	}
	if err := w.Close(); err != nil {
		t.Fatal(err)
	}