```Python
@lru_cache
def say_hi(name: str, salutation: str = "Ms."):
    return f"Hello {salutation} {name}"
```

your program could execute like this:

```mermaid
sequenceDiagram

participant code as Code
participant function as say_hi()
participant execute as Execute function

    rect rgba(0, 255, 0, .1)
        code ->> function: say_hi(name="Camila")

例如，如果您有一个函数：
```Python
@lru_cache
def say_hi(name: str, salutation: str = "Ms."):
    return f"Hello {salutation} {name}"
```

您的程序可以像这样执行：

```mermaid
sequenceDiagram

participant code as Code
participant function as say_hi()
participant execute as Execute function

    rect rgba(0, 255, 0, .1)
        code ->> function: say_hi(name="Camila")
        function ->> execute: 执行函数代码

from typing import Optional


def say_hi(name: Optional[str]):

from typing import Union


def say_hi(name: Union[str, None] = None):
    if name is not None:
        print(f"Hey {name}!")
    else:

```Python
@lru_cache
def say_hi(name: str, salutation: str = "Ms."):
    return f"Hello {salutation} {name}"
```

könnte Ihr Programm so ausgeführt werden:

```mermaid
sequenceDiagram

participant code as Code
participant function as say_hi()
participant execute as Funktion ausgeführt

    rect rgba(0, 255, 0, .1)
        code ->> function: say_hi(name="Camila")

def say_hi(name: str | None = None):
    if name is not None:
        print(f"Hey {name}!")
    else:

```Python
say_hi()  # Oh, nein, das löst einen Fehler aus! 😱
```

Der `name` Parameter wird **immer noch benötigt** (nicht *optional*), weil er keinen Default-Wert hat. `name` akzeptiert aber dennoch `None` als Wert:

```Python
say_hi(name=None)  # Das funktioniert, None is gültig 🎉
```

🖼, 🚥 👆 ✔️ 🔢:

```Python
@lru_cache
def say_hi(name: str, salutation: str = "Ms."):
    return f"Hello {salutation} {name}"
```

👆 📋 💪 🛠️ 💖 👉:

```mermaid
sequenceDiagram

participant code as Code
participant function as say_hi()
participant execute as Execute function

    rect rgba(0, 255, 0, .1)
        code ->> function: say_hi(name="Camila")

```Python
say_hi()  # ওহ না, এটি একটি ত্রুটি নিক্ষেপ করবে! 😱
```

`name` প্যারামিটারটি **এখনও আবশ্যিক** (নন-অপশনাল) কারণ এটির কোনো ডিফল্ট মান নেই। তবুও, `name` এর মান হিসেবে `None` গ্রহণযোগ্য:

```Python
say_hi(name=None)  # এটি কাজ করে, None বৈধ 🎉
```

def say_hi(name: str | None):