from typing_extensions import Annotated


def say_hello(name: Annotated[str, "this is just metadata"]) -> str:

from typing import Annotated


def say_hello(name: Annotated[str, "this is just metadata"]) -> str:

For example, if you want to read or manipulate the request body before it is processed by your application.

/// danger

This is an "advanced" feature.

If you are just starting with **FastAPI** you might want to skip this section.

///

## Use cases

Some use cases include:

Prefer to use the `Annotated` version if possible.

///

```Python hl_lines="8-9"
{!> ../../docs_src/dependencies/tutorial005.py!}
```

////

It declares an optional query parameter `q` as a `str`, and then it just returns it.

This is quite simple (not very useful), but will help us focus on how the sub-dependencies work.

## Second dependency, "dependable" and "dependant"

You could also use `from starlette import status`.

**FastAPI** provides the same `starlette.status` as `fastapi.status` just as a convenience for you, the developer. But it comes directly from Starlette.

///

## Tags

You can add tags to your *path operation*, pass the parameter `tags` with a `list` of `str` (commonly just one `str`):

//// tab | Python 3.10+

```Python hl_lines="15  20  25"

  }

  @Retention(RetentionPolicy.RUNTIME)
  private @interface NotBlank {}

  /** Class for testing constructor, static method and instance method. */
  @SuppressWarnings("unused") // most are called by reflection
  private static class Prepender {

    private final String prefix;
    private final int times;

    Prepender(@NotBlank @Nullable String prefix, int times) throws NullPointerException {

  }

  @Retention(RetentionPolicy.RUNTIME)
  private @interface NotBlank {}

  /** Class for testing constructor, static method and instance method. */
  @SuppressWarnings("unused") // most are called by reflection
  private static class Prepender {

    private final String prefix;
    private final int times;

    Prepender(@NotBlank @Nullable String prefix, int times) throws NullPointerException {

    try {
      long remainingNanos = unit.toNanos(timeout);
      long end = System.nanoTime() + remainingNanos;

      while (true) {
        try {
          // CountDownLatch treats negative timeouts just like zero.
          return latch.await(remainingNanos, NANOSECONDS);
        } catch (InterruptedException e) {
          interrupted = true;
          remainingNanos = end - System.nanoTime();
        }
      }

Um die Zertifikate zu erneuern, muss das erneuernde Programm der Behörde (Let's Encrypt) **nachweisen**, dass es diese Domain tatsächlich **besitzt und kontrolliert**.

Um dies zu erreichen und den unterschiedlichen Anwendungsanforderungen gerecht zu werden, gibt es mehrere Möglichkeiten. Einige beliebte Methoden sind:

* **Einige DNS-Einträge ändern**.

based on screen height and width\n$rfs-two-dimensional: false !default;\n\n// Factor of decrease\n$rfs-factor: 10 !default;\n\n@if type-of($rfs-factor) != \"number\" or $rfs-factor <= 1 {\n  @error \"`#{$rfs-factor}` is not a valid  $rfs-factor, it must be greater than 1.\";\n}\n\n// Generate enable or disable classes. Possibilities: false, \"enable\" or \"disable\"\n$rfs-class: false !default;\n\n// 1 rem = $rfs-rem-value px\n$rfs-rem-value: 16 !default;\n\n// Safari iframe resize bug: https://g...