from fastapi import FastAPI
from pydantic import BaseModel

app = FastAPI()


class Item(BaseModel):
    name: str
    description: str | None = None
    price: float
    tax: float | None = None

    class Config:
        schema_extra = {
            "examples": [
                {
                    "name": "Foo",
                    "description": "A very nice Item",
                    "price": 35.4,

from typing import Any, Union

from fastapi import FastAPI
from pydantic import BaseModel

app = FastAPI()


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


@app.post("/items/", response_model=Item)
async def create_item(item: Item) -> Any:
    return item


@app.get("/items/", response_model=list[Item])

async def override_dependency(q: str | None = None):
    return {"q": q, "skip": 5, "limit": 10}


app.dependency_overrides[common_parameters] = override_dependency


def test_override_in_items():
    response = client.get("/items/")
    assert response.status_code == 200
    assert response.json() == {
        "message": "Hello Items!",
        "params": {"q": None, "skip": 5, "limit": 10},
    }

from pydantic import BaseModel
from typing_extensions import Annotated

app = FastAPI()


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


@app.put("/items/{item_id}")
async def update_item(
    *,
    item_id: int,
    item: Annotated[
        Item,
        Body(
            examples=[
                {

from typing import Annotated, Union

from fastapi import Body, FastAPI
from pydantic import BaseModel

app = FastAPI()


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


@app.put("/items/{item_id}")
async def update_item(
    *,
    item_id: int,
    item: Annotated[
        Item,
        Body(
            examples=[
                {

class CallableGenDependency:
    def __call__(self, value: str) -> Generator[str, None, None]:
        yield value


class AsyncCallableDependency:
    async def __call__(self, value: str) -> str:
        return value


class AsyncCallableGenDependency:
    async def __call__(self, value: str) -> AsyncGenerator[str, None]:
        yield value


class MethodsDependency:

from typing import Set, Union

from fastapi import FastAPI
from pydantic import BaseModel

app = FastAPI()


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


@app.post(
    "/items/",
    response_model=Item,
    summary="Create an item",
    response_description="The created item",
)

from contextvars import ContextVar

import peewee

DATABASE_NAME = "test.db"
db_state_default = {"closed": None, "conn": None, "ctx": None, "transactions": None}
db_state = ContextVar("db_state", default=db_state_default.copy())


class PeeweeConnectionState(peewee._ConnectionState):
    def __init__(self, **kwargs):
        super().__setattr__("_state", db_state)
        super().__init__(**kwargs)

    def __setattr__(self, name, value):

```

デフォルト値`None`を`Query(default=None)`に置き換える必要があるので、`Query`の最初の引数はデフォルト値を定義するのと同じです。

なので:

```Python
q: Optional[str] = Query(default=None)
```

...を以下と同じようにパラメータをオプションにします:

```Python
q: Optional[str] = None
```

しかし、これはクエリパラメータとして明示的に宣言しています。

!!! info "情報"
    FastAPIは以下の部分を気にすることを覚えておいてください:

    ```Python
    = None
    ```

    もしくは:

In this scenario, each one of the cleaners (including you) would be a processor, doing their part of the job.