Here we define the config `env_file` inside of your Pydantic `Settings` class, and set the value to the filename with the dotenv file we want to use.

### Creating the `Settings` only once with `lru_cache`

```Python hl_lines="10-11" title="app/main.py"
{!../../../docs_src/bigger_applications/app/main.py!}
```

!!! info
    `users.router` contains the `APIRouter` inside of the file `app/routers/users.py`.

    And `items.router` contains the `APIRouter` inside of the file `app/routers/items.py`.

With `app.include_router()` we can add each `APIRouter` to the main `FastAPI` application.

#### Union

You can declare that a variable can be any of **several types**, for example, an `int` or a `str`.

In Python 3.6 and above (including Python 3.10) you can use the `Union` type from `typing` and put inside the square brackets the possible types to accept.

Quando você usa o _script_ em `./scripts/docs.py` com o comando `live` ele somente exibe os arquivos e traduções disponíveis para a linguagem atual.

Mas uma vez que você tenha concluído, você poderá testar tudo como se parecesse _online_.

Para fazer isso, primeiro construa toda a documentação:

<div class="termy">

```console
// Use o comando "build-all", isso leverá um tempinho
$ python ./scripts/docs.py build-all

Updating es

After this, the client and the server have an **encrypted TCP connection**, this is what TLS provides. And then they can use that connection to start the actual **HTTP communication**.

And that's what **HTTPS** is, it's just plain **HTTP** inside a **secure TLS connection** instead of a pure (unencrypted) TCP connection.

!!! tip
    Notice that the encryption of the communication happens at the **TCP level**, not at the HTTP level.

### HTTPS Request

型を使用した標準的なPythonを記述します:

```Python
from datetime import date

from pydantic import BaseModel

# Declare a variable as a str
# and get editor support inside the function
def main(user_id: str):
    return user_id


# A Pydantic model
class User(BaseModel):
    id: int
    name: str
    joined: date
```

これは以下のように用いられます:

```Python

```

...& 🛠️ ⚫️ ⏮️ 👆 💽 📊 & 🎓 (📊 ✳, ✳ ⚖️ 🙆 🎏).

!!! tip

    👉 👑 ⏸ 👈 👆 🔜 ✔️ 🔀 🚥 👆 💚 ⚙️ 🎏 💽.

### ✍ 🇸🇲 `engine`

🥇 🔁 ✍ 🇸🇲 "🚒".

👥 🔜 ⏪ ⚙️ 👉 `engine` 🎏 🥉.

```Python hl_lines="8-10"
{!../../../docs_src/sql_databases/sql_app/database.py!}
```

#### 🗒

❌:

```Python

Buna ek olarak Python'un **Veri Bilimi**, Makine Öğrenimi ve özellikle Derin Öğrenme için ana dil olduğu gerçeği, FastAPI'yi Veri Bilimi / Makine Öğrenimi web API'leri ve uygulamaları için çok iyi bir seçenek haline getirir.

Production'da nasıl oldugunu görmek için şu bölüme bakın [Deployment](deployment/index.md){.internal-link target=_blank}.

## `async` ve `await`

* <a href="https://jinja.palletsprojects.com" target="_blank"><code>jinja2</code></a> - Bắt buộc nếu bạn muốn sử dụng cấu hình template engine mặc định.

But you can also declare the `Response` that you want to be used, in the *path operation decorator*.

The contents that you return from your *path operation function* will be put inside of that `Response`.