set FILE_ARG=
:arg_loop
if "%~1" == "-f" (
  set "FILE_ARG=%~2"
  shift
  goto process_file_arg
)
if "%~1" == "--file" (
  set "FILE_ARG=%~2"
  shift
  goto process_file_arg
)
@REM If none of the above, skip the argument
shift
if not "%~1" == "" (
  goto arg_loop
) else (
  goto findBaseDir
)

:process_file_arg
if "%FILE_ARG%" == "" (
  goto findBaseDir
)

So, you can confirm if you are in the correct virtual environment.

/// tip

It's easy to activate one virtual environment, get one Python, and then **go to another project**.

And the second project **wouldn't work** because you are using the **incorrect Python**, from a virtual environment for another project.

Wir hatten diese Typannotation:

//// tab | Python 3.10+

```Python
q: str | None = None
```

////

//// tab | Python 3.9+

```Python
q: Union[str, None] = None
```

////

Was wir tun werden, ist, dies mit `Annotated` zu wrappen, sodass es zu:

//// tab | Python 3.10+

```Python
q: Annotated[str | None] = None
```

////

//// tab | Python 3.9+

```Python

Tínhamos esta anotação de tipo:

//// tab | Python 3.10+

```Python
q: str | None = None
```

////

//// tab | Python 3.9+

```Python
q: Union[str, None] = None
```

////

O que faremos é envolver isso com `Annotated`, para que fique assim:

//// tab | Python 3.10+

```Python
q: Annotated[str | None] = None
```

////

//// tab | Python 3.9+

```Python

class Item(BaseModel):
    name: Union[str, None] = None
    description: Union[str, None] = None
    price: Union[float, None] = None
    tax: float = 10.5
    tags: list[str] = []


items = {
    "foo": {"name": "Foo", "price": 50.2},
    "bar": {"name": "Bar", "description": "The bartenders", "price": 62, "tax": 20.2},
    "baz": {"name": "Baz", "description": None, "price": 50.2, "tax": 10.5, "tags": []},
}

    name: str = Field(index=True)
    age: Union[int, None] = Field(default=None, index=True)


class Hero(HeroBase, table=True):
    id: Union[int, None] = Field(default=None, primary_key=True)
    secret_name: str


class HeroPublic(HeroBase):
    id: int


class HeroCreate(HeroBase):
    secret_name: str


class HeroUpdate(HeroBase):
    name: Union[str, None] = None
    age: Union[int, None] = None

            "price": 50.5,
            "description": None,
            "tax": None,
        },
        "user": {"username": "Dave", "full_name": None},
    }


def test_put_missing_body(client: TestClient):
    response = client.put("/items/5")
    assert response.status_code == 422
    assert response.json() == {
        "detail": [
            {
                "input": None,
                "loc": [

   *   <li>The visible constructor or visible static factory method with the most parameters is used
   *       to construct the sample instances. In case of tie, the candidate constructors or
   *       factories are tried one after another until one can be used to construct sample
   *       instances.
   *   <li>For the constructor or static factory method used to construct instances, it's checked

# Without aliases


@app.get("/optional-str")
async def read_optional_str(p: Annotated[Optional[str], Header()] = None):
    return {"p": p}


class HeaderModelOptionalStr(BaseModel):
    p: Optional[str] = None


@app.get("/model-optional-str")
async def read_model_optional_str(p: Annotated[HeaderModelOptionalStr, Header()]):
    return {"p": p.p}

app = FastAPI()


class Image(BaseModel):
    url: str
    name: str


class Item(BaseModel):
    name: str
    description: str | None = None
    price: float
    tax: float | None = None
    tags: set[str] = set()
    image: Image | None = None


@app.put("/items/{item_id}")
async def update_item(item_id: int, item: Item):
    results = {"item_id": item_id, "item": item}