{!> ../../../docs_src/bigger_applications/app_an/dependencies.py!}
    ```

=== "Python 3.8+ nicht annotiert"

    !!! tip "Tipp"
        Bevorzugen Sie die `Annotated`-Version, falls möglich.

    ```Python hl_lines="1  4-6" title="app/dependencies.py"
    {!> ../../../docs_src/bigger_applications/app/dependencies.py!}
    ```

!!! tip "Tipp"

---

Nochmal, es handelt sich hier um sehr technische Details, die Ihnen helfen, falls Sie danach gesucht haben.

module = "fastapi.tests.*"
ignore_missing_imports = true
check_untyped_defs = true

[[tool.mypy.overrides]]
module = "docs_src.*"
disallow_incomplete_defs = false
disallow_untyped_defs = false
disallow_untyped_calls = false

[tool.pytest.ini_options]
addopts = [
  "--strict-config",
  "--strict-markers",
  "--ignore=docs_src",
]
xfail_strict = true
junit_family = "xunit2"
filterwarnings = [
    "error",

Und jedes Attribut hat einen Typ.

Dann erzeugen Sie eine Instanz dieser Klasse mit einigen Werten, und Pydantic validiert die Werte, konvertiert sie in den passenden Typ (falls notwendig) und gibt Ihnen ein Objekt mit allen Daten.

Und Sie erhalten volle Editor-Unterstützung für dieses Objekt.

Ein Beispiel aus der offiziellen Pydantic Dokumentation:

=== "Python 3.10+"

* ✏ Fix typos in Deployment Guide. PR [#3975](https://github.com/tiangolo/fastapi/pull/3975) by [@ghandic](https://github.com/ghandic).
* 📝 Update docs with pip install calls when using extras with brackets, use quotes for compatibility with Zsh. PR [#3131](https://github.com/tiangolo/fastapi/pull/3131) by [@tomwei7](https://github.com/tomwei7).

The process that happens when your API app calls the *external API* is named a "callback". Because the software that the external developer wrote sends a request to your API and then your API *calls back*, sending a request to an *external API* (that was probably created by the same developer).

### Other utility functions

Any other utility function that you call directly can be created with normal `def` or `async def` and FastAPI won't affect the way you call it.

This is in contrast to the functions that FastAPI calls for you: *path operation functions* and dependencies.

    !!! tip
        Prefer to use the `Annotated` version if possible.

    ```Python hl_lines="19"
    {!> ../../../docs_src/dependencies/tutorial002.py!}
    ```

**FastAPI** calls the `CommonQueryParams` class. This creates an "instance" of that class and the instance will be passed as the parameter `commons` to your function.

## Type annotation vs `Depends`

          path: ./site/**

  # https://github.com/marketplace/actions/alls-green#why
  docs-all-green:  # This job does nothing and is only used for the branch protection
    if: always()
    needs:
      - build-docs
    runs-on: ubuntu-latest
    steps:
      - name: Decide whether the needed jobs succeeded or failed
        uses: re-actors/alls-green@release/v1
        with:
          jobs: ${{ toJSON(needs) }}

    !!! tip
        Prefer to use the `Annotated` version if possible.

    ```Python hl_lines="1  10"
    {!> ../../../docs_src/settings/app03/main.py!}
    ```

Then for any subsequent calls of `get_settings()` in the dependencies for the next requests, instead of executing the internal code of `get_settings()` and creating a new `Settings` object, it will return the same object that was returned on the first call, again and again.