assert response.json() == {
        "name": "Baz",
        "description": None,
        "price": 50.2,
        "tax": 10.5,
        "tags": [],
    }


def test_put(client: TestClient):
    response = client.put(
        "/items/bar", json={"name": "Barz", "price": 3, "description": None}
    )
    assert response.json() == {
        "name": "Barz",
        "description": None,
        "price": 3,

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

ваша программа может выполняться так:

```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")

configure<MavenPublishBaseExtension> {
  publishToMavenCentral(automaticRelease = true)
  signAllPublications()
  pom {
    name.set(project.name)
    description.set("Square’s meticulous HTTP client for Java and Kotlin.")
    url.set("https://square.github.io/okhttp/")
    licenses {
      license {
        name.set("The Apache Software License, Version 2.0")
        url.set("https://www.apache.org/licenses/LICENSE-2.0.txt")

com.my
edu.my
gov.my
mil.my
name.my
net.my
org.my

// mz : http://www.uem.mz/
// Submitted by registry <******@****.***>
mz
ac.mz
adv.mz
co.mz
edu.mz
gov.mz
mil.mz
net.mz
org.mz

// na : http://www.na-nic.com.na/
na
alt.na
co.na
com.na
gov.na
net.na
org.na

// name : has 2nd-level tlds, but there's no list of them

from typing import Optional


def say_hi(name: Optional[str]):
    print(f"Hey {name}!")
```

Параметр `name` визначено як `Optional[str]`, але він не є необов'язковим, ви не можете викликати функцію без цього параметра:

```Python
say_hi()  # О ні, це викликає помилку! 😱
```

Параметр `name` все ще обов'язковий (не «необов'язковий»), тому що не має значення за замовчуванням. Водночас `name` приймає `None` як значення:

```Python

    assert response.json() == {
        "name": "mixed model3 name",
        "ref2": {
            "ref": {"foo": "mixed model foo", "bar": "mixed model bar"},
        },
    }


def test_nested_include_mixed_dict():
    response = client.get("/mixed_dict")
    assert response.status_code == 200, response.text
    assert response.json() == {
        "name": "mixed_dict model3 name",
        "ref2": {

        jApiField.name >> 'field'
        jApiField.jApiClass >> jApiClassifier
        jApiMethod.name >> 'method'
        jApiMethod.jApiClass >> jApiClassifier
        jApiConstructor.name >> 'ApiTest'
        jApiConstructor.jApiClass >> jApiClassifier

        incubatingAnnotation.fullyQualifiedName >> Incubating.name
        deprecatedAnnotation.fullyQualifiedName >> Deprecated.name

        oldBase = instanceScopedPool.get(OldBase.name)
        newBase = instanceScopedPool.get(NewBase.name)
        newSuper = instanceScopedPool.get(NewSuper.name)
        newIncubatingBase = instanceScopedPool.get(NewIncubatingBase.name)
        internalInterface = instanceScopedPool.get(InternalInterface.name)
        incubatingInterface = instanceScopedPool.get(IncubatingInterface.name)

```python
from typing import Optional


def say_hi(name: Optional[str]):
    print(f"Hey {name}!")
```

El parámetro `name` está definido como `Optional[str]`, pero **no es opcional**, no puedes llamar a la función sin el parámetro:

```Python
say_hi()  # ¡Oh, no, esto lanza un error! 😱
```

    response = client.put("/items/foo", json={"name": "Wrestlers"})
    assert response.status_code == 200, response.text
    assert response.json() == {"name": "Wrestlers", "size": None}


def test_create(client: TestClient):
    response = client.put("/items/red", json={"name": "Chillies"})
    assert response.status_code == 201, response.text