min_length=3,
        max_length=50,
        pattern="^fixedquery$",
        deprecated=True,
    ),
):
    results = {"items": [{"item_id": "Foo"}, {"item_id": "Bar"}]}
    if q:
        results.update({"q": q})

    return x_key


@app.get("/items/", dependencies=[Depends(verify_token), Depends(verify_key)])
async def read_items():

            description="Query string for the items to search in the database that have a good match",
            min_length=3,
        ),
    ] = None,
):
    results = {"items": [{"item_id": "Foo"}, {"item_id": "Bar"}]}
    if q:
        results.update({"q": q})

            {
                "name": "Foo",
                "description": "A very nice Item",
                "price": 35.4,
                "tax": 3.2,
            },
            {
                "name": "Bar",
                "price": "35.4",
            },
            {
                "name": "Baz",
                "price": "thirty five point four",
            },
        ],
    ),
):

from typing import Union

from fastapi import Depends, FastAPI

app = FastAPI()


fake_items_db = [{"item_name": "Foo"}, {"item_name": "Bar"}, {"item_name": "Baz"}]


class CommonQueryParams:
    def __init__(self, q: Union[str, None] = None, skip: int = 0, limit: int = 100):
        self.q = q
        self.skip = skip
        self.limit = limit


@app.get("/items/")
async def read_items(commons: CommonQueryParams = Depends()):

    Integer foo = new Integer(Integer.MAX_VALUE - 10);
    Integer bar = new Integer(Integer.MAX_VALUE - 10);

    assertNotSame(foo, bar);
    assertEquals(foo, bar);

    List<Integer> list = asList(3, foo, bar, -1);
    List<Integer> result = numberOrdering.leastOf(list, list.size());
    assertEquals(ImmutableList.of(-1, 3, foo, bar), result);
  }

  public void testLeastOfIterator_ties() {

    Integer foo = new Integer(Integer.MAX_VALUE - 10);
    Integer bar = new Integer(Integer.MAX_VALUE - 10);

    assertNotSame(foo, bar);
    assertEquals(foo, bar);

    List<Integer> list = asList(3, foo, bar, -1);
    List<Integer> result = numberOrdering.leastOf(list, list.size());
    assertEquals(ImmutableList.of(-1, 3, foo, bar), result);
  }

  public void testLeastOfIterator_ties() {

```Python hl_lines="9"
{!> ../../docs_src/header_params/tutorial003.py!}
```

////

与*路径操作*通信时，以下面的方式发送两个 HTTP 请求头：

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

响应结果是：

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

## 小结

使用 `Header` 声明请求头的方式与 `Query`、`Path` 、`Cookie` 相同。

from typing import Union

from fastapi import Depends, FastAPI

app = FastAPI()


fake_items_db = [{"item_name": "Foo"}, {"item_name": "Bar"}, {"item_name": "Baz"}]


class CommonQueryParams:
    def __init__(self, q: Union[str, None] = None, skip: int = 0, limit: int = 100):
        self.q = q
        self.skip = skip
        self.limit = limit


@app.get("/items/")

from typing import Annotated, Union

from fastapi import Depends, FastAPI

app = FastAPI()


fake_items_db = [{"item_name": "Foo"}, {"item_name": "Bar"}, {"item_name": "Baz"}]


class CommonQueryParams:
    def __init__(self, q: Union[str, None] = None, skip: int = 0, limit: int = 100):
        self.q = q
        self.skip = skip
        self.limit = limit


@app.get("/items/")