### Import `Query` and `Annotated`

To achieve that, first import:

* `Query` from `fastapi`
* `Annotated` from `typing` (or from `typing_extensions` in Python below 3.9)

//// tab | Python 3.10+

In Python 3.9 or above, `Annotated` is part of the standard library, so you can import it from `typing`.

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

////

from typing import Optional

from dirty_equals import IsDict
from fastapi import Depends, FastAPI, Security
from fastapi.security import OAuth2, OAuth2PasswordRequestFormStrict
from fastapi.testclient import TestClient
from pydantic import BaseModel

app = FastAPI()

reusable_oauth2 = OAuth2(
    flows={
        "password": {
            "tokenUrl": "token",
            "scopes": {"read:users": "Read the users", "write:users": "Create users"},

import json
from typing import Dict

import pytest
from fastapi import BackgroundTasks, Depends, FastAPI
from fastapi.responses import StreamingResponse
from fastapi.testclient import TestClient

app = FastAPI()
state = {
    "/async": "asyncgen not started",
    "/sync": "generator not started",
    "/async_raise": "asyncgen raise not started",
    "/sync_raise": "generator raise not started",
    "context_a": "not started a",

<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}")

```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}")

<div class="termy">

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

---> 100%
```

</div>

## Exemplo

### Crie

* Crie um arquivo `main.py` com:

```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):

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

---> 100%
```

</div>

## Àpẹẹrẹ

### Ṣẹ̀dá rẹ̀

* Ṣẹ̀dá fáìlì `main.py (èyí tíí ṣe, akọkọ.py)` pẹ̀lú:

```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>

## مثال

### ایجاد کنید
* فایلی به نام `main.py` با محتوای زیر ایجاد کنید:

```Python
from typing import Union

from fastapi import FastAPI

app = FastAPI()


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


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

{!../../docs_src/python_types/tutorial005.py!}
```

### 嵌套类型

有些容器数据结构可以包含其他的值，比如 `dict`、`list`、`set` 和 `tuple`。它们内部的值也会拥有自己的类型。

你可以使用 Python 的 `typing` 标准库来声明这些类型以及子类型。

它专门用来支持这些类型提示。

#### 列表

例如，让我们来定义一个由 `str` 组成的 `list` 变量。

从 `typing` 模块导入 `List`（注意是大写的 `L`）：

```Python hl_lines="1"
{!../../docs_src/python_types/tutorial006.py!}
```

同样以冒号（`:`）来声明这个变量。

输入 `List` 作为类型。