from typing import Annotated

from fastapi import FastAPI, Header, HTTPException
from pydantic import BaseModel

fake_secret_token = "coneofsilence"

fake_db = {
    "foo": {"id": "foo", "title": "Foo", "description": "There goes my hero"},
    "bar": {"id": "bar", "title": "Bar", "description": "The bartenders"},
}

app = FastAPI()


class Item(BaseModel):
    id: str
    title: str
    description: str | None = None

from collections.abc import Awaitable
from contextvars import ContextVar
from typing import Any, Callable, Optional

from fastapi import Depends, FastAPI, Request, Response
from fastapi.testclient import TestClient

legacy_request_state_context_var: ContextVar[Optional[dict[str, Any]]] = ContextVar(
    "legacy_request_state_context_var", default=None
)

app = FastAPI()


async def set_up_request_state_dependency():

from typing import Union

from fastapi import Body, FastAPI, Query
from fastapi.testclient import TestClient

app = FastAPI()


@app.get("/query")
def read_query(q: Union[str, None]):
    return q


@app.get("/explicit-query")
def read_explicit_query(q: Union[str, None] = Query()):
    return q


@app.post("/body-embed")
def send_body_embed(b: Union[str, None] = Body(embed=True)):
    return b

// ARM64SpecialOperand returns the internal representation of a special operand.
func ARM64SpecialOperand(name string) arm64.SpecialOperand {
	if arm64SpecialOperand == nil {
		// Generate mapping when function is first called.
		arm64SpecialOperand = map[string]arm64.SpecialOperand{}
		for opd := arm64.SPOP_BEGIN; opd < arm64.SPOP_END; opd++ {
			arm64SpecialOperand[opd.String()] = opd
		}

Wie funktioniert das? Schauen wir uns das mal an. 🤓

### Typannotationen und Tooling { #type-annotations-and-tooling }

Sehen wir uns zunächst an, wie Editor, mypy und andere Tools dies sehen würden.

from typing import Annotated

from fastapi import Depends, FastAPI
from fastapi.testclient import TestClient

app = FastAPI()


async def common_parameters(q: str | None = None, skip: int = 0, limit: int = 100):
    return {"q": q, "skip": skip, "limit": limit}


@app.get("/items/")
async def read_items(commons: Annotated[dict, Depends(common_parameters)]):
    return {"message": "Hello Items!", "params": commons}

from typing import Optional

from fastapi import FastAPI, Security
from fastapi.security import HTTPAuthorizationCredentials, HTTPBearer
from fastapi.testclient import TestClient

app = FastAPI()

security = HTTPBearer(auto_error=False)


@app.get("/users/me")
def read_current_user(
    credentials: Optional[HTTPAuthorizationCredentials] = Security(security),
):
    if credentials is None:

from typing import Optional

from fastapi import FastAPI, Security
from fastapi.security import OAuth2AuthorizationCodeBearer
from fastapi.testclient import TestClient

app = FastAPI()

oauth2_scheme = OAuth2AuthorizationCodeBearer(
    authorizationUrl="authorize",
    tokenUrl="token",
    description="OAuth2 Code Bearer",
    auto_error=True,
)


@app.get("/items/")

from typing import Optional

from fastapi import FastAPI, Security
from fastapi.security import OAuth2PasswordBearer
from fastapi.testclient import TestClient

app = FastAPI()

oauth2_scheme = OAuth2PasswordBearer(tokenUrl="/token", auto_error=False)


@app.get("/items/")
async def read_items(token: Optional[str] = Security(oauth2_scheme)):
    if token is None:
        return {"msg": "Create an account first"}
    return {"token": token}

しかし、Pythonには型や「タイプパラメータ」を使ってリストを宣言する方法があります:

### typingの`List`をインポート

まず、Pythonの標準の`typing`モジュールから`List`をインポートします:

{* ../../docs_src/body_nested_models/tutorial002.py hl[1] *}

### タイプパラメータを持つ`List`の宣言

`list`や`dict`、`tuple`のようなタイプパラメータ（内部の型）を持つ型を宣言するには:

* `typing`モジュールからそれらをインストールします。
* 角括弧（`[`と`]`）を使って「タイプパラメータ」として内部の型を渡します:

```Python
from typing import List

my_list: List[str]
```