router = APIRouter()


@router.get("/a", responses={501: {"description": "Error 1"}})
async def a():
    return "a"


@router.get(
    "/b",
    responses={
        502: {"description": "Error 2"},
        "4XX": {"description": "Error with range, upper"},
    },
)
async def b():
    return "b"


@router.get(
    "/c",
    responses={
        "400": {"description": "Error with str"},

        execute ->> code: return the result
    end

    rect rgba(0, 255, 255, .1)
        code ->> function: say_hi(name="Camila")
        function ->> code: return stored result
    end

    rect rgba(0, 255, 0, .1)
        code ->> function: say_hi(name="Rick")
        function ->> execute: execute function code
        execute ->> code: return the result
    end

Those worker processes would be the ones running your application, they would perform the main computations to receive a **request** and return a **response**, and they would load anything you put in variables in RAM.

<img src="/img/deployment/concepts/process-ram.drawio.svg">

        def serialize_datetime(self, dt_field: datetime):
            return dt_field.replace(microsecond=0, tzinfo=timezone.utc).isoformat()

    app = FastAPI()
    model = ModelWithDatetimeField(dt_field=datetime(2019, 1, 1, 8))

    @app.get("/model", response_model=ModelWithDatetimeField)
    def get_model():
        return model

    client = TestClient(app)
    with client:

app = FastAPI()


def get_header(*, someheader: str = Header()):
    return someheader


def get_something_else(*, someheader: str = Depends(get_header)):
    return f"{someheader}123"


@app.get("/")
def get_deps(dep1: str = Depends(get_header), dep2: str = Depends(get_something_else)):
    return {"dep1": dep1, "dep2": dep2}


client = TestClient(app)


def test_response():

async def response_status_setter(response: Response):
    response.status_code = 201


async def parent_dep(result=Depends(response_status_setter)):
    return result


@app.get("/", dependencies=[Depends(parent_dep)])
async def get_main():
    return {"msg": "Hello World"}


client = TestClient(app)


def test_dependency_set_status_code():
    response = client.get("/")

from .utils import needs_py310


class Dep:
    def __call__(self, request: Request):
        return "test"


@needs_py310
def test_stringified_annotations():
    app = FastAPI()

    client = TestClient(app)

    @app.get("/test/")
    def call(test: Annotated[str, Depends(Dep())]):
        return {"test": test}

    response = client.get("/test")

async def validation_exception_handler(request: Request, exc: RequestValidationError):
    return JSONResponse(
        status_code=422,
        content=jsonable_encoder({"detail": exc.errors(), "body": exc.body}),
    )


class Item(BaseModel):
    title: str
    size: int


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

app = FastAPI()


@app.post("/urlencoded")
async def post_url_encoded(age: Annotated[int | None, Form()] = None):
    return age


@app.post("/multipart")
async def post_multi_part(
    age: Annotated[int | None, Form()] = None,
    file: Annotated[bytes | None, File()] = None,
):
    return {"file": file, "age": age}


client = TestClient(app)


def test_form_default_url_encoded():

    response_model=ResponseModel,
)
async def response_model_has_default_factory_return_dict():
    return {"code": 200}


@app.get(
    "/response_model_has_default_factory_return_model",
    response_model=ResponseModel,
)
async def response_model_has_default_factory_return_model():
    return ResponseModel()


client = TestClient(app)


def test_response_model_has_default_factory_return_dict():