<arg>-J--add-exports=jdk.compiler/com.sun.tools.javac.main=ALL-UNNAMED</arg>
              <arg>-J--add-exports=jdk.compiler/com.sun.tools.javac.model=ALL-UNNAMED</arg>
              <arg>-J--add-exports=jdk.compiler/com.sun.tools.javac.parser=ALL-UNNAMED</arg>
              <arg>-J--add-exports=jdk.compiler/com.sun.tools.javac.processing=ALL-UNNAMED</arg>

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()
```

Hepsi sadece **Python** standartlarına dayalıdır.

Örnek olarak, `int` tanımlamak için:

```Python
item_id: int
```

ya da daha kompleks herhangi bir python modelini tanımlayabiliriz, örneğin `Item` modeli için:

```Python
item: Item
```

...ve sadece kısa bir parametre tipi belirterek elde ettiklerimiz:

* Editör desteğiyle birlikte:
    * Otomatik tamamlama.
    * Tip kontrolü.

   * stripes, the intended concurrency level, and the typical number of keys used in a {@code
   * bulkGet(keys)} operation. See <a href="http://www.mathpages.com/home/kmath199.htm">Balls in
   * Bins model</a> for mathematical formulas that can be used to estimate the probability of
   * collisions.
   *
   * @param keys arbitrary non-null keys

```console
$ fastapi dev main.py

<span style="color: green;">INFO</span>:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
```

</div>

그런 다음 `/docs` UI로 이동하면, **FastAPI**가 해당 **model들**을 사용하여 API **문서를 생성**하는 것으르 확인할 수 있습니다. 또한 이 모델들은 데이터를 직렬화하고 검증하는 데에도 사용됩니다.

<div class="screenshot">
<img src="/img/tutorial/sql-databases/image01.png">
</div>

## 여러 모델로 애플리케이션 업데이트

import java.util.LinkedHashMap;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.Set;
import java.util.function.UnaryOperator;

import org.apache.maven.impl.model.DefaultInterpolator;

/**
 * Enhancement of the standard <code>Properties</code>
 * managing the maintain of comments, etc.
 */
public class MavenProperties extends AbstractMap<String, String> {

import java.util.LinkedHashMap;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.Set;
import java.util.function.UnaryOperator;

import org.apache.maven.impl.model.DefaultInterpolator;

/**
 * Enhancement of the standard <code>Properties</code>
 * managing the maintain of comments, etc.
 */
@Deprecated
public class MavenProperties extends AbstractMap<String, String> {

	Float  DataType = "float"
	String DataType = "string"
	Time   DataType = "time"
	Bytes  DataType = "bytes"
)

const DefaultAutoIncrementIncrement int64 = 1

// Field is the representation of model schema's field
type Field struct {
	Name                   string
	DBName                 string
	BindNames              []string
	EmbeddedBindNames      []string
	DataType               DataType

Nur Standard-**Python**.

Zum Beispiel für ein `int`:

```Python
item_id: int
```

oder für ein komplexeres `Item`-Modell:

```Python
item: Item
```

... und mit dieser einen Deklaration erhalten Sie:

* Editor-Unterstützung, einschließlich:
    * Code-Vervollständigung.
    * Typprüfungen.

```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 = {