Чтобы достичь этого, первым делом нам нужно импортировать:

* `Query` из пакета `fastapi`:
* `Annotated` из пакета `typing` (или из `typing_extensions` для Python ниже 3.9)

=== "Python 3.10+"

    В Python 3.9 или выше, `Annotated` является частью стандартной библиотеки, таким образом вы можете импортировать его из `typing`.

    ```Python hl_lines="1  3"
    {!> ../../../docs_src/query_params_str_validations/tutorial002_an_py310.py!}

```console
$ pip install "uvicorn[standard]"

---> 100%
```

</div>

## Példa

### Hozd létre

* Hozz létre a `main.py` fájlt a következő tartalommal:

```Python
from typing import Union

from fastapi import FastAPI

app = FastAPI()


@app.get("/")
def read_root():
    return {"Hello": "World"}


@app.get("/items/{item_id}")

```console
$ pip install "uvicorn[standard]"

---> 100%
```

</div>

## Ejemplo

### Créalo

* Crea un archivo `main.py` con:

```Python
from fastapi import FastAPI
from typing import Union

app = FastAPI()


@app.get("/")
def read_root():
    return {"Hello": "World"}


@app.get("/items/{item_id}")
def read_item(item_id: int, q: Union[str, None] = None):

### `Query` und `Annotated` importieren

Importieren Sie zuerst:

* `Query` von `fastapi`
* `Annotated` von `typing` (oder von `typing_extensions` in Python unter 3.9)

=== "Python 3.10+"

    In Python 3.9 oder darüber, ist `Annotated` Teil der Standardbibliothek, also können Sie es von `typing` importieren.

    ```Python hl_lines="1  3"
    {!> ../../../docs_src/query_params_str_validations/tutorial002_an_py310.py!}

politely; but she added, to herself, `Why, they're only a pack of
cards, after all.  I needn't be afraid of them!'

  `And who are THESE?' said the Queen, pointing to the three
gardeners who were lying round the rosetree; for, you see, as
they were lying on their faces, and the pattern on their backs
was the same as the rest of the pack, she could not tell whether
they were gardeners, or soldiers, or courtiers, or three of her
own children.

<div class="termy">

```console
$ pip install "uvicorn[standard]"

---> 100%
```

</div>

## উদাহরণ

### তৈরি

- `main.py` নামে একটি ফাইল তৈরি করুন:

```Python
from typing import Union

from fastapi import FastAPI

app = FastAPI()


@app.get("/")
def read_root():
    return {"Hello": "World"}


@app.get("/items/{item_id}")

        // array.
        while (mid > -1 && this[mid] != '\n'.code.toByte()) {
          mid--
        }
        mid++

        // Now look for the ending '\n'.
        var end = 1
        while (this[mid + end] != '\n'.code.toByte()) {
          end++
        }
        val publicSuffixLength = mid + end - mid

* Bump GCE ContainerVM to container-vm-v20170201 to address CVE-2016-9962. ([#40828](https://github.com/kubernetes/kubernetes/pull/40828), [@zmerlynn](https://github.com/zmerlynn))
* Adding vmdk file extension for vmDiskPath in vsphere DeleteVolume ([#40538](https://github.com/kubernetes/kubernetes/pull/40538), [@divyenpatel](https://github.com/divyenpatel))

```

*`resolveDependencies` task resolves dependencies for all platforms including dependencies downloaded by plugins.*

Keep in mind:

- If you’re adding a dependency with OS mentioned in an artifact name (`darwin`, `mac`, `osx`, `linux`, `windows`), remember to add them to 

* Path `prefix`: `/items`.
* `tags`: (just one tag: `items`).
* Extra `responses`.
* `dependencies`: they all need that `X-Token` dependency we created.

So, instead of adding all that to each *path operation*, we can add it to the `APIRouter`.

```Python hl_lines="5-10  16  21" title="app/routers/items.py"
{!../../../docs_src/bigger_applications/app/routers/items.py!}
```