placeholder: |
        from fastapi import FastAPI

        app = FastAPI()


        @app.get("/")
        def read_root():
            return {"Hello": "World"}
      render: python
    validations:
      required: true
  - type: textarea
    id: description
    attributes:
      label: Description
      description: |

        @app.post("/")
        async def root(f: bytes = File()):
            return f  # pragma: nocover


def test_incorrect_multipart_installed_multi_form(monkeypatch):
    monkeypatch.delattr("multipart.multipart.parse_options_header", raising=False)
    with pytest.raises(RuntimeError, match=multipart_incorrect_install_error):
        app = FastAPI()

        @app.post("/")

        app = FastAPI()

        @app.get("/", response_model=NonPydanticModel)
        def read_root():
            pass  # pragma: nocover


def test_invalid_response_model_sub_type_raises():
    with pytest.raises(FastAPIError):
        app = FastAPI()

        @app.get("/", response_model=List[NonPydanticModel])
        def read_root():
            pass  # pragma: nocover

        "openapi": "3.1.0",
        "info": {"title": "FastAPI", "version": "0.1.0"},
        "paths": {
            "/": {
                "get": {
                    "summary": "Root",
                    "operationId": "root__get",
                    "responses": {
                        "200": {
                            "description": "Successful Response",

from pydantic_settings import BaseSettings


class Settings(BaseSettings):
    openapi_url: str = "/openapi.json"


settings = Settings()

app = FastAPI(openapi_url=settings.openapi_url)


@app.get("/")
def root():

    obj = ModelWithPath(path=PureWindowsPath("/foo", "bar"))
    assert jsonable_encoder(obj) == {"path": "\\foo\\bar"}


@needs_pydanticv1
def test_encode_root():
    class ModelWithRoot(BaseModel):
        __root__: str

    model = ModelWithRoot(__root__="Foo")
    assert jsonable_encoder(model) == "Foo"


@needs_pydanticv2
def test_decimal_encoder_float():
    data = {"value": Decimal(1.23)}

        <mxGraphModel dx="2481" dy="1867" grid="1" gridSize="10" guides="1" tooltips="1" connect="1" arrows="1" fold="1" page="1" pageScale="1" pageWidth="1920" pageHeight="1200" math="0" shadow="0">
            <root>
                <mxCell id="0"/>
                <mxCell id="1" parent="0"/>
                <mxCell id="2" value="" style="rounded=0;whiteSpace=wrap;html=1;fontStyle=1;strokeWidth=4;" parent="1" vertex="1">

            ),
        )
    assert response.status_code == 200, response.text
    assert response.json() == {"filenames": ["test.txt", "test2.txt"]}


@needs_py39
def test_get_root(app: FastAPI):
    client = TestClient(app)
    response = client.get("/")
    assert response.status_code == 200, response.text
    assert b"<form" in response.content


@needs_py39

## 基础 **FastAPI** 应用

* 创建应用文件夹，例如 `./fastapideta/`，进入文件夹

### FastAPI 代码

* 创建包含如下代码的 `main.py`：

```Python
from fastapi import FastAPI

app = FastAPI()


@app.get("/")
def read_root():
    return {"Hello": "World"}


@app.get("/items/{item_id}")
def read_item(item_id: int):
    return {"item_id": item_id}
```

### 需求项

在文件夹里新建包含如下内容的 `requirements.txt` 文件：

```text

from fastapi import FastAPI, Request

app = FastAPI(root_path="/api/v1")


@app.get("/app")
def read_main(request: Request):