You can customize that function. It takes an `APIRoute` and outputs a string.

For example, here it is using the first tag (you will probably have only one tag) and the *path operation* name (the function name).

You can then pass that custom function to **FastAPI** as the `generate_unique_id_function` parameter:

=== "Python 3.9+"

import pytest
from dirty_equals import IsDict
from fastapi.testclient import TestClient


@pytest.fixture(name="client")
def get_client():
    from docs_src.bigger_applications.app_an.main import app

    client = TestClient(app)
    return client


def test_users_token_jessica(client: TestClient):
    response = client.get("/users?token=jessica")
    assert response.status_code == 200

import pytest
from dirty_equals import IsDict
from fastapi.testclient import TestClient

from ...utils import needs_py39


@pytest.fixture(name="client")
def get_client():
    from docs_src.bigger_applications.app_an_py39.main import app

    client = TestClient(app)
    return client


@needs_py39
def test_users_token_jessica(client: TestClient):
    response = client.get("/users?token=jessica")

*在这里，我们在路径操作函数*和依赖项中都使用着 SQLAlchemy 模型，它将与外部数据库进行通信。

这会需要一些“等待时间”。

但是由于 SQLAlchemy 不具有`await`直接使用的兼容性，因此类似于：

```Python
user = await db.query(User).first()
```

...相反，我们可以使用：

```Python
user = db.query(User).first()
```

然后我们应该声明*路径操作函数*和不带 的依赖关系`async def`，只需使用普通的`def`，如下：

```Python hl_lines="2"
@app.get("/users/{user_id}", response_model=schemas.User)

            """
        ),
    ] = None,
    *,
    use_cache: Annotated[
        bool,
        Doc(
            """
            By default, after a dependency is called the first time in a request, if
            the dependency is declared again for the rest of the request (for example
            if the dependency is needed by several dependencies), the value will be

$ python ./scripts/docs.py serve

Warning: this is a very simple server. For development, use mkdocs serve instead.
This is here only to preview a site with translations already built.
Make sure you run the build-all command first.
Serving at: http://127.0.0.1:8008
```

</div>

## 💯

📤 ✍ 👈 👆 💪 🏃 🌐 💯 🌐 📟 &amp; 🏗 💰 📄 🕸:

<div class="termy">

```console
$ bash scripts/test-cov-html.sh
```

### 步骤 1：导入 `FastAPI`

```Python hl_lines="1"
{!../../../docs_src/first_steps/tutorial001.py!}
```

`FastAPI` 是一个为你的 API 提供了所有功能的 Python 类。

!!! note "技术细节"
    `FastAPI` 是直接从 `Starlette` 继承的类。

    你可以通过 `FastAPI` 使用所有的 Starlette 的功能。

### 步骤 2：创建一个 `FastAPI`「实例」

```Python hl_lines="3"
{!../../../docs_src/first_steps/tutorial001.py!}
```

这里的变量 `app` 会是 `FastAPI` 类的一个「实例」。

# Security - First Steps

Let's imagine that you have your **backend** API in some domain.

And you have a **frontend** in another domain or in a different path of the same domain (or in a mobile application).

And you want to have a way for the frontend to authenticate with the backend, using a **username** and **password**.

We can use **OAuth2** to build that with **FastAPI**.

Nils Lindemann <******@****.***> 1713469999 +0200

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"},