### Klassen als Typen { #classes-as-types }

Sie können auch eine Klasse als Typ einer Variablen deklarieren.

Nehmen wir an, Sie haben eine Klasse `Person`, mit einem Namen:

{* ../../docs_src/python_types/tutorial010_py310.py hl[1:3] *}

Dann können Sie eine Variable vom Typ `Person` deklarieren:

{* ../../docs_src/python_types/tutorial010_py310.py hl[6] *}

Und wiederum bekommen Sie die volle Editor-Unterstützung:

Je pense que `Union[SomeType, None]` est plus explicite quant à sa signification.

Il ne s'agit que des mots et des noms. Mais ces mots peuvent influencer la manière dont vous et vos coéquipiers pensez au code.

À titre d'exemple, prenons cette fonction :

```python
from typing import Optional

	person := Person{Name: "person", Addresses: []Address{address1, address2}}
	DB.Create(&person)

	var addresses1 []Address
	if err := DB.Model(&person).Association("Addresses").Find(&addresses1); err != nil || len(addresses1) != 2 {
		t.Fatalf("Failed to find address, got error %v, length: %v", err, len(addresses1))
	}

	if err := DB.Model(&person).Association("Addresses").Delete(&person.Addresses[0]); err != nil {

            Request((mockServer.secureEndpoint + "/person?name=peter").toHttpUrl()),
          ).execute()

      assertThat(response.body.string()).contains("Peter the person")
      assertThat(response.protocol).isEqualTo(Protocol.HTTP_1_1)
    }
  }

  @Test
  fun testUrlConnectionDirect() {
    testRequest {
      val url = URI(mockServer.endpoint + "/person?name=peter").toURL()

from pydantic import BaseModel, Field, ValidationError


class Person:
    def __init__(self, name: str):
        self.name = name


class Pet:
    def __init__(self, owner: Person, name: str):
        self.owner = owner
        self.name = name


@dataclass
class Item:
    name: str
    count: int


class DictablePerson(Person):
    def __iter__(self):

        full_name: str

        model_config = {"from_attributes": True}

    app = FastAPI()

    @app.post("/people/", response_model=PersonRead)
    def create_person(person: PersonCreate) -> Any:
        db_person = Person.model_validate(person)
        return db_person

    client = TestClient(app)

    person_data = {"name": "Dive", "lastname": "Wilson"}
    response = client.post("/people/", json=person_data)

 *
 * {@snippet :
 * public enum PersonFunnel implements Funnel<Person> {
 *   INSTANCE;
 *   public void funnel(Person person, PrimitiveSink into) {
 *     into.putUnencodedChars(person.getFirstName())
 *         .putUnencodedChars(person.getLastName())
 *         .putInt(person.getAge());
 *   }
 * }
 * }
 *
 * @author Dimitris Andreou
 * @since 11.0
 */
@Beta

```JSON
{
  "detail": [
    {
      "type": "int_parsing",
      "loc": [
        "path",
        "item_id"
      ],
      "msg": "Input should be a valid integer, unable to parse string as an integer",
      "input": "foo"
    }
  ]
}
```

Der Pfad-Parameter `item_id` hatte den Wert „foo“, was kein `int` ist.

  @Test fun invalidCharacters() {
    assertThat(parse(url, "a\u0000b=cd")).isNull()
    assertThat(parse(url, "ab=c\u0000d")).isNull()
    assertThat(parse(url, "a\u0001b=cd")).isNull()
    assertThat(parse(url, "ab=c\u0001d")).isNull()
    assertThat(parse(url, "a\u0009b=cd")).isNull()
    assertThat(parse(url, "ab=c\u0009d")).isNull()
    assertThat(parse(url, "a\u001fb=cd")).isNull()
    assertThat(parse(url, "ab=c\u001fd")).isNull()

            MediaType.parse("text/plain; charset=UTF-8"),
            MediaType.parse("text/plain ; charset=utf-8"),
            MediaType.parse("text/plain; charset =UTF-8"),
            MediaType.parse("text/plain; charset= UTF-8"),
            MediaType.parse("text/plain; charset  =  UTF-8"),
            MediaType.parse("text/plain; charset=\tUTF-8"))