```

!!! tip
    The code for `override_get_db()` is almost exactly the same as for `get_db()`, but in `override_get_db()` we use the `TestingSessionLocal` for the testing database instead.

## Test the app

Then we can just test the app as normally.

```Python hl_lines="32-47"
{!../../../docs_src/sql_databases/sql_app/tests/test_sql_app.py!}
```

=== "Python 3.10+"

    ```Python
    {!> ../../../docs_src/app_testing/app_b_an_py310/main.py!}
    ```

=== "Python 3.9+"

    ```Python
    {!> ../../../docs_src/app_testing/app_b_an_py39/main.py!}
    ```

=== "Python 3.8+"

    ```Python
    {!> ../../../docs_src/app_testing/app_b_an/main.py!}
    ```

=== "Python 3.10+ non-Annotated"

    !!! tip

RUN pip install fastapi uvicorn

EXPOSE 80

COPY ./app /app

CMD ["uvicorn", "app.main:app", "--host", "0.0.0.0", "--port", "80"]
```

## Créer le code **FastAPI**.

* Créer un répertoire `app` et y entrer.
* Créez un fichier `main.py` avec :

```Python
from typing import Optional

from fastapi import FastAPI

app = FastAPI()


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

    👆 💼, 👉 👨‍🎨 💬 **FastAPI** 👈 🔢 🔛 🔗 **➡** `/` ⏮️ **🛠️** `get`.

    ⚫️ "**➡ 🛠️ 👨‍🎨**".

👆 💪 ⚙️ 🎏 🛠️:

* `@app.post()`
* `@app.put()`
* `@app.delete()`

& 🌅 😍 🕐:

* `@app.options()`
* `@app.head()`
* `@app.patch()`
* `@app.trace()`

!!! tip
    👆 🆓 ⚙️ 🔠 🛠️ (🇺🇸🔍 👩‍🔬) 👆 🎋.

    **FastAPI** 🚫 🛠️ 🙆 🎯 🔑.

    ℹ 📥 🎁 📄, 🚫 📄.

In general, ASGI middlewares are classes that expect to receive an ASGI app as the first argument.

So, in the documentation for third-party ASGI middlewares they will probably tell you to do something like:

```Python
from unicorn import UnicornMiddleware

app = SomeASGIApp()

new_app = UnicornMiddleware(app, some_config="rainbow")
```

    </div>

!!! note
    The command `uvicorn main:app` refers to:

    * `main`: the file `main.py` (the Python "module").
    * `app`: the object created inside of `main.py` with the line `app = FastAPI()`.

    It is equivalent to:

    ```Python
    from main import app
    ```

!!! warning
    Uvicorn and others support a `--reload` option that is useful during development.

그러나 다음과 같이 다른 파일을 가져올 때는 호출되지 않습니다.

```Python
from myapp import app
```

#### 추가 세부사항

파일 이름이 `myapp.py`라고 가정해 보겠습니다.

다음과 같이 실행하면

<div class="termy">

```console
$ python myapp.py
```

</div>

Python에 의해 자동으로 생성된 파일의 내부 변수 `__name__`은 문자열 `"__main__"`을 값으로 갖게 됩니다.

따라서 섹션

```Python
    uvicorn.run(app, host="0.0.0.0", port=8000)
```

이 실행됩니다.

---

# 📨 👔 📟

🎏 🌌 👆 💪 ✔ 📨 🏷, 👆 💪 📣 🇺🇸🔍 👔 📟 ⚙️ 📨 ⏮️ 🔢 `status_code` 🙆 *➡ 🛠️*:

* `@app.get()`
* `@app.post()`
* `@app.put()`
* `@app.delete()`
* ♒️.

```Python hl_lines="6"
{!../../../docs_src/response_status_code/tutorial001.py!}
```

!!! note
    👀 👈 `status_code` 🔢 "👨‍🎨" 👩‍🔬 (`get`, `post`, ♒️). 🚫 👆 *➡ 🛠️ 🔢*, 💖 🌐 🔢 & 💪.

`status_code` 🔢 📨 🔢 ⏮️ 🇺🇸🔍 👔 📟.

!!! info

The first thing you should do is to "pin" the version of **FastAPI** you are using to the specific latest version that you know works correctly for your application.

For example, let's say you are using version `0.45.0` in your app.

If you use a `requirements.txt` file you could specify the version with:

```txt
fastapi==0.45.0
```

that would mean that you would use exactly the version `0.45.0`.

Or you could also pin it with:

# 测试事件：启动 - 关闭

使用 `TestClient` 和 `with` 语句，在测试中运行事件处理器（`startup` 与 `shutdown`）。

```Python hl_lines="9-12  20-24"
{!../../../docs_src/app_testing/tutorial003.py!}