app = FastAPI()


@app.get("/items/")
async def read_items(
    q: Annotated[Union[str, None], Query(min_length=3, max_length=50)] = None,
):
    results = {"items": [{"item_id": "Foo"}, {"item_id": "Bar"}]}
    if q:
        results.update({"q": q})

{* ../../docs_src/header_params/tutorial003.py hl[9] *}

다음과 같은 두 개의 HTTP 헤더를 전송하여 해당 *경로* 와 통신할 경우:

```
X-Token: foo
X-Token: bar
```

응답은 다음과 같습니다:

```JSON
{
    "X-Token values": [
        "bar",
        "foo"
    ]
}
```

## 요약

`Header`는 `Query`, `Path`, `Cookie`와 동일한 패턴을 사용하여 선언합니다.

label:
	JB	-4(PC) // JCS -4(PC)
	JB	label // JCS 17

// LTYPEC spec3	{ outcode($1, &$2); }
	JCS	2(PC)
	JMP	-4(PC)
	JCS	2(PC)
	JMP	label // JMP 17
	JCS	2(PC)
	JMP	foo+4(SB)
	JCS	2(PC)
	JMP	bar<>+4(SB)
	JCS	2(PC)
	JMP	bar<>+4(SB)(R11*4)
	JCS	2(PC)
	JMP	*4(SP) // JMP 4(SP)
	JCS	2(PC)
	JMP	*(R12) // JMP (R12)
	JCS	2(PC)
//	JMP	*(R12*4) // TODO: This line is silently dropped on the floor!
	JCS	2(PC)

@app.get("/items/")
async def read_items(
    q: Annotated[
        str | None, Query(min_length=3, max_length=50, pattern="^fixedquery$")
    ] = None,
):
    results = {"items": [{"item_id": "Foo"}, {"item_id": "Bar"}]}
    if q:
        results.update({"q": q})

app = FastAPI()


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

            min_length=3,
            max_length=50,
            pattern="^fixedquery$",
            deprecated=True,
        ),
    ] = None,
):
    results = {"items": [{"item_id": "Foo"}, {"item_id": "Bar"}]}
    if q:
        results.update({"q": q})

        self.fixed_content = fixed_content

    def __call__(self, q: str = ""):
        if q:
            return self.fixed_content in q
        return False


checker = FixedContentQueryChecker("bar")


@app.get("/query-checker/")
async def read_query_check(fixed_content_included: bool = Depends(checker)):

Тогда при таком URL:

```
http://localhost:8000/items/?q=foo&q=bar
```

вы получите множественные значения query-параметра `q` (`foo` и `bar`) в виде Python-`list` внутри вашей *функции обработки пути*, в *параметре функции* `q`.

Таким образом, ответ на этот URL будет:

```JSON
{
  "q": [
    "foo",
    "bar"
  ]
}
```

/// tip | Совет

func ExampleEqualFold() {
	fmt.Println(bytes.EqualFold([]byte("Go"), []byte("go")))
	// Output: true
}

func ExampleFields() {
	fmt.Printf("Fields are: %q", bytes.Fields([]byte("  foo bar  baz   ")))
	// Output: Fields are: ["foo" "bar" "baz"]
}

func ExampleFieldsFunc() {
	f := func(c rune) bool {
		return !unicode.IsLetter(c) && !unicode.IsNumber(c)
	}

from fastapi import FastAPI, Response, status

app = FastAPI()

tasks = {"foo": "Listen to the Bar Fighters"}


@app.put("/get-or-create-task/{task_id}", status_code=200)
def get_or_create_task(task_id: str, response: Response):
    if task_id not in tasks:
        tasks[task_id] = "This didn't exist before"
        response.status_code = status.HTTP_201_CREATED