from pydantic import BaseModel

app = FastAPI()


class Cookies(BaseModel):
    model_config = {"extra": "forbid"}

    session_id: str
    fatebook_tracker: str | None = None
    googall_tracker: str | None = None


@app.get("/items/")
async def read_items(cookies: Cookies = Cookie()):

from typing import Annotated

from fastapi import Cookie, FastAPI
from pydantic import BaseModel

app = FastAPI()


class Cookies(BaseModel):
    session_id: str
    fatebook_tracker: str | None = None
    googall_tracker: str | None = None


@app.get("/items/")
async def read_items(cookies: Annotated[Cookies, Cookie()]):

由于这种情况下（不使用 `Annotated`）我们必须把函数中的默认值 `None` 替换为 `Query()`，因此需要通过参数 `Query(default=None)` 来设置默认值，它起到同样的作用（至少对 FastAPI 来说）。

所以：

```Python
q: str | None = Query(default=None)
```

...会让参数变成可选，默认值为 `None`，等同于：

```Python
q: str | None = None
```

但使用 `Query` 的版本会显式把它声明为一个查询参数。

然后，我们可以向 `Query` 传入更多参数。本例中是适用于字符串的 `max_length` 参数：

	ctx, cancel := context.WithCancel(context.Background())
	go func() {
		select {
		case <-ctx1.Done():
		case <-ctx2.Done():
		// The lock acquirer decides to cancel, exit this goroutine
		case <-ctx.Done():
		}

		cancel()
	}()
	return ctx, cancel
}

func (ld sharedLock) GetLock(ctx context.Context) (context.Context, context.CancelFunc) {

    Args:
      app (ASGI application): ASGI application
      max_content_size (optional): the maximum content size allowed in bytes, None for no limit
    """

    def __init__(self, app: APIRouter, max_content_size: int | None = None):
        self.app = app
        self.max_content_size = max_content_size

    def receive_wrapper(self, receive):
        received = 0

        async def inner():

from fastapi import FastAPI, Query

app = FastAPI()


@app.get("/items/")
async def read_items(
    q: str | None = Query(default=None, title="Query string", min_length=3),
):
    results = {"items": [{"item_id": "Foo"}, {"item_id": "Bar"}]}
    if q:
        results.update({"q": q})

from typing import Annotated

from fastapi import FastAPI, Query

app = FastAPI()


@app.get("/items/")
async def read_items(q: Annotated[str | None, Query(max_length=50)] = None):
    results = {"items": [{"item_id": "Foo"}, {"item_id": "Bar"}]}
    if q:
        results.update({"q": q})

class SubItem(BaseModel):
    subname: str
    sub_description: str | None = None
    tags: list[str] = []
    model_config = {"json_schema_serialization_defaults_required": True}


class Item(BaseModel):
    name: str
    description: str | None = None
    sub: SubItem | None = None
    model_config = {"json_schema_serialization_defaults_required": True}

					done = true
				}
			}
		case <-ctx.Done():
			// Capture timedout locks as failed or took too long
			locksFailed++
			if locksFailed > tolerance {
				// We know that we are not going to get the lock anymore,
				// so exit out and release any locks that did get acquired
				done = true
			}
		}

		if done {
			break
		}
	}

from typing import Annotated

from fastapi import Body, FastAPI
from pydantic import BaseModel

app = FastAPI()


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


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