from fastapi import FastAPI, File, UploadFile
from typing_extensions import Annotated

app = FastAPI()


@app.post("/files/")
async def create_file(file: Annotated[bytes, File(description="A file read as bytes")]):
    return {"file_size": len(file)}


@app.post("/uploadfile/")
async def create_upload_file(
    file: Annotated[UploadFile, File(description="A file read as UploadFile")],
):

from typing import Any

from fastapi import FastAPI
from pydantic import BaseModel, EmailStr

app = FastAPI()


class UserIn(BaseModel):
    username: str
    password: str
    email: EmailStr
    full_name: str | None = None


class UserOut(BaseModel):
    username: str
    email: EmailStr
    full_name: str | None = None


@app.post("/user/", response_model=UserOut)
async def create_user(user: UserIn) -> Any:

from fastapi import FastAPI
from pydantic import BaseModel


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


app = FastAPI()


@app.post("/items/")
def create_item(item: Item):
    return item


@app.get("/items/")
def read_items() -> list[Item]:
    return [
        Item(
            name="Portal Gun",
            description="Device to travel through the multi-rick-verse",

---> 100%
```

</div>

这将在虚拟环境中安装所有依赖和本地版本的 FastAPI。

#### 使用本地 FastAPI

如果你创建一个导入并使用 FastAPI 的 Python 文件，然后使用虚拟环境中的 Python 运行它，它将使用你本地的 FastAPI 源码。

并且如果你更改该本地 FastAPI 的源码，由于它是通过 `-e` 安装的，当你再次运行那个 Python 文件，它将使用你刚刚编辑过的最新版本的 FastAPI。

这样，你不必再去重新"安装"你的本地版本即可测试所有更改。

/// note | "技术细节"

仅当你使用此项目中的 `requirements.txt` 安装而不是直接使用 `pip install fastapi` 安装时，才会发生这种情况。

It will already be installed with FastAPI.

```Python hl_lines="3-4"
{!> ../../docs_src/query_params_str_validations/tutorial002_an.py!}
```

////

/// info

FastAPI added support for `Annotated` (and started recommending it) in version 0.95.0.

If you have an older version, you would get errors when trying to use `Annotated`.

Ela é importada/incluída diretamente no FastAPI para que você possa importá-la do `fastapi` e evitar a importação acidental da alternativa `BackgroundTask` (sem o `s` no final) de `starlette.background`.

Usando apenas `BackgroundTasks` (e não `BackgroundTask`), é então possível usá-la como um parâmetro de _função de operação de caminho_ e deixar o **FastAPI** cuidar do resto para você, assim como ao usar o objeto `Request` diretamente.

It is imported/included directly into FastAPI so that you can import it from `fastapi` and avoid accidentally importing the alternative `BackgroundTask` (without the `s` at the end) from `starlette.background`.

By only using `BackgroundTasks` (and not `BackgroundTask`), it's then possible to use it as a *path operation function* parameter and have **FastAPI** handle the rest for you, just like when using the `Request` object directly.

class UJSONResponse(JSONResponse):
    """
    JSON response using the high-performance ujson library to serialize data to JSON.

    Read more about it in the
    [FastAPI docs for Custom Response - HTML, Stream, File, others](https://fastapi.tiangolo.com/advanced/custom-response/).
    """

    def render(self, content: Any) -> bytes:
        assert ujson is not None, "ujson must be installed to use UJSONResponse"

            200,
            {"strange_header": "FastAPI test"},
        ),
        (
            "/items",
            {"strange-header": "Not really underscore"},
            200,
            {"strange_header": None},
        ),
    ],
)
def test(path, headers, expected_status, expected_response):
    response = client.get(path, headers=headers)
    assert response.status_code == expected_status

from fastapi import FastAPI
from pydantic import BaseModel


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


app = FastAPI(separate_input_output_schemas=False)


@app.post("/items/")
def create_item(item: Item):
    return item


@app.get("/items/")
def read_items() -> list[Item]:
    return [
        Item(
            name="Portal Gun",