from pydantic_settings import BaseSettings, SettingsConfigDict


class Settings(BaseSettings):
    app_name: str = "Awesome API"
    admin_email: str
    items_per_user: int = 50

{!../../docs_src/python_types/tutorial009.py!}
```

`str` yerine `Optional[str]` kullanmak editorün bu değerin her zaman `str` tipinde değil bazen `None` tipinde de olabileceğini belirtir ve hataları tespit etmemizde yardımcı olur.

#### Generic tipler

Köşeli parantez içinde tip parametreleri alan bu türler, örneğin:

* `List`
* `Tuple`
* `Set`
* `Dict`
* `Optional`
* ...and others.

		{"s.authorInfo.yearRange[0]", []interface{}{1890.0, 1920.0, 1881.0}},
		{"s.publicationHistory[0].pages", []interface{}{256.0, 336.0, Missing{}}},
	}
	for i, tc := range cases {
		t.Run(tc.str, func(t *testing.T) {
			jp := JSONPath{}
			err := p.ParseString(tc.str, &jp)
			// fmt.Println(jp)
			if err != nil {
				t.Fatalf("parse failed!: %d %v %s", i, err, tc)
			}

			// Read only the first json object from the file

app = FastAPI()

items = {"foo": {"name": "Fighters", "size": 6}, "bar": {"name": "Tenders", "size": 3}}


@app.put("/items/{item_id}")
async def upsert_item(
    item_id: str,
    name: Annotated[Union[str, None], Body()] = None,
    size: Annotated[Union[int, None], Body()] = None,
):
    if item_id in items:
        item = items[item_id]
        item["name"] = name
        item["size"] = size

from fastapi.encoders import jsonable_encoder
from pydantic import BaseModel

app = FastAPI()


class Item(BaseModel):
    name: Union[str, None] = None
    description: Union[str, None] = None
    price: Union[float, None] = None
    tax: float = 10.5
    tags: list[str] = []


items = {
    "foo": {"name": "Foo", "price": 50.2},
    "bar": {"name": "Bar", "description": "The bartenders", "price": 62, "tax": 20.2},

        @Override
        Optional<String> chop(String str) {
          return i.chop(str).or(you.chop(str));
        }
      };
    }

    abstract Optional<String> chop(String str);

    static Chopper suffix(String suffix) {
      return new Chopper() {
        @Override
        Optional<String> chop(String str) {
          if (str.endsWith(suffix)) {

from fastapi.testclient import TestClient
from pydantic import BaseModel, HttpUrl

app = FastAPI()


class Invoice(BaseModel):
    id: str
    title: Optional[str] = None
    customer: str
    total: float


class InvoiceEvent(BaseModel):
    description: str
    paid: bool


class InvoiceEventReceived(BaseModel):
    ok: bool


invoices_callback_router = APIRouter()

from typing import Annotated

from fastapi import FastAPI, Form

app = FastAPI()


@app.post("/login/")
async def login(username: Annotated[str, Form()], password: Annotated[str, Form()]):

app = FastAPI()


def _get_client_key(client_id: str = Query(...)) -> str:
    return f"{client_id}_key"


def _get_client_tag(client_id: Optional[str] = Query(None)) -> Optional[str]:
    if client_id is None:
        return None
    return f"{client_id}_tag"


@app.get("/foo")
def foo_handler(
    client_key: str = Depends(_get_client_key),
    client_tag: Optional[str] = Depends(_get_client_tag),
):

* 💽 🛠️
* 💽 🔬
* 🏧 🧾

## 🎁 🆎 & 🔬

↖️ ⚪️➡️ 😐 ⭐ 🆎 💖 `str`, `int`, `float`, ♒️. 👆 💪 ⚙️ 🌅 🏗 ⭐ 🆎 👈 😖 ⚪️➡️ `str`.

👀 🌐 🎛 👆 ✔️, 🛒 🩺 <a href="https://docs.pydantic.dev/latest/concepts/types/" class="external-link" target="_blank">Pydantic 😍 🆎</a>. 👆 🔜 👀 🖼 ⏭ 📃.

🖼, `Image` 🏷 👥 ✔️ `url` 🏑, 👥 💪 📣 ⚫️ ↩️ `str`, Pydantic `HttpUrl`:

//// tab | 🐍 3️⃣.6️⃣ &amp; 🔛

```Python hl_lines="4  10"