Just standard **Python**.

For example, for an `int`:

```Python
item_id: int
```

or for a more complex `Item` model:

```Python
item: Item
```

...and with that single declaration you get:

* Editor support, including:
    * Completion.
    * Type checks.
* Validation of data:

Go 1.21 made it an error for html/template actions to appear inside of an ECMAScript 6
template literal, controlled by the
[`jstmpllitinterp` setting](/pkg/html/template#hdr-Security_Model).
This behavior was backported to Go 1.19.8+ and Go 1.20.3+.

Go 1.21 introduced a limit on the maximum number of MIME headers and multipart
forms, controlled by the

Chỉ cần sử dụng các chuẩn của **Python**.

Ví dụ, với một tham số kiểu `int`:

```Python
item_id: int
```

hoặc với một model `Item` phức tạp hơn:

```Python
item: Item
```

...và với định nghĩa đơn giản đó, bạn có được:

* Sự hỗ trợ từ các trình soạn thảo, bao gồm:
    * Completion.
    * Kiểm tra kiểu dữ liệu.

`RequestValidationError`はPydanticの<a href="https://docs.pydantic.dev/latest/concepts/models/#error-handling" class="external-link" target="_blank">`ValidationError`</a>のサブクラスです。

**FastAPI** は`response_model`でPydanticモデルを使用していて、データにエラーがあった場合、ログにエラーが表示されるようにこれを使用しています。

しかし、クライアントやユーザーはそれを見ることはありません。その代わりに、クライアントはHTTPステータスコード`500`の「Internal Server Error」を受け取ります。

/libraries/tools/kotlin-gradle-plugin-idea-proto/ "Kotlin Build Tools"
/libraries/tools/kotlin-gradle-plugin-integration-tests/ "Kotlin Build Tools" "Kotlin Apple Ecosystem"
/libraries/tools/kotlin-gradle-plugin-model/ "Kotlin Build Tools"
/libraries/tools/kotlin-gradle-plugin-npm-versions-codegen/ Ilya.Goncharov
/libraries/tools/kotlin-gradle-plugin-test-utils-embeddable/ "Kotlin Build Tools"

```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
my_user: User = User(id=3, name="John Doe", joined="2018-07-19")

second_user_data = {

        .build()
    writeHttpResponse(socket, sink, webSocketResponse)

    // Adapt the request and response into our Request and Response domain model.
    val scheme = if (request.handshake != null) "https" else "http"
    val authority = request.headers["Host"] // Has host and port.
    val fancyRequest =
      Request.Builder()
        .url("$scheme://$authority/")

在这里，我们在 Pydantic 的 `Settings` 类中创建了一个名为 `Config` 的类，并将 `env_file` 设置为我们想要使用的 dotenv 文件的文件名。

!!! tip
    `Config` 类仅用于 Pydantic 配置。您可以在<a href="https://docs.pydantic.dev/latest/api/config/" class="external-link" target="_blank">Pydantic Model Config</a>中阅读更多相关信息。

### 使用 `lru_cache` 仅创建一次 `Settings`

从磁盘中读取文件通常是一项耗时的（慢）操作，因此您可能希望仅在首次读取后并重复使用相同的设置对象，而不是为每个请求都读取它。

但是，每次执行以下操作：

```Python
Settings()
```

Just standard **Python**.

For example, for an `int`:

```Python
item_id: int
```

or for a more complex `Item` model:

```Python
item: Item
```

...and with that single declaration you get:

* Editor support, including:
    * Completion.
    * Type checks.
* Validation of data:

    (including a physical distribution medium), accompanied by a
    written offer, valid for at least three years and valid for as
    long as you offer spare parts or customer support for that product
    model, to give anyone who possesses the object code either (1) a
    copy of the Corresponding Source for all the software in the
    product that is covered by this License, on a durable physical