func timeZone(offset time.Duration) *time.Location {
	const (
		minOffset   = -12 * time.Hour  // E.g., Baker island at -12:00
		maxOffset   = +14 * time.Hour  // E.g., Line island at +14:00
		offsetAlias = 15 * time.Minute // E.g., Nepal at +5:45
	)
	offset = offset.Round(offsetAlias)
	if offset < minOffset || maxOffset < offset {
		offset = 0
	}

app = FastAPI()


class Item(BaseModel):
    name: str
    price: float
    is_offer: Union[bool, None] = None


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


@app.get("/items/{item_id}")
def read_item(item_id: int, q: Union[str, None] = None):
    return {"item_id": item_id, "q": q}


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

This is not a limitation of **FastAPI**, it's part of the HTTP protocol.

///

## Optional File Upload

You can make a file optional by using standard type annotations and setting a default value of `None`:

//// tab | Python 3.10+

```Python hl_lines="9  17"
{!> ../../docs_src/request_files/tutorial001_02_an_py310.py!}
```

////

//// tab | Python 3.9+

```Python hl_lines="9  17"

   * actual {@code y} values of the data and the values predicted by the fit for the {@code x}
   * values (i.e. it is the square root of the mean of the squares of the vertical distances between
   * the data points and the best fit line). For this fit, this error is a fraction {@code sqrt(1 -
   * R*R)} of the population standard deviation of {@code y}, where {@code R} is the Pearson's

}

/*
 Fixes for a number of issues with the default stylesheet.
 */

/* Fixes huge font size in <pre>{@code} blocks. */
pre code {
    font-size:inherit;
}

/*
 Fixes issue with no blank line before <pre> in class-level Javadoc
 when the <pre> is preceded by a block of text with no <p>.
 */
.description .block pre {
    margin-top:1em;

   * actual {@code y} values of the data and the values predicted by the fit for the {@code x}
   * values (i.e. it is the square root of the mean of the squares of the vertical distances between
   * the data points and the best fit line). For this fit, this error is a fraction {@code sqrt(1 -
   * R*R)} of the population standard deviation of {@code y}, where {@code R} is the Pearson's

### Short

It has sensible **defaults** for everything, with optional configurations everywhere. All the parameters can be fine-tuned to do what you need and to define the API you need.

But by default, it all **"just works"**.

### Validation

* Validation for most (or all?) Python **data types**, including:
    * JSON objects (`dict`).

    * Liczb (`int`, `float`) z wartościami minimalnymi, maksymalnymi, itp.

* Walidacja bardziej egzotycznych typów danych, takich jak:
    * URL.
    * Email.
    * UUID.
    * ...i inne.

Cała walidacja jest obsługiwana przez ugruntowaną i solidną bibliotekę **Pydantic**.

### Bezpieczeństwo i uwierzytelnianie

				tagMap = t.ToMap()
			}
			for _, kv := range r.Flags.Filter.Tags {
				for t, v := range tagMap {
					if kv.Match(BatchJobKV{Key: t, Value: v}) {
						return true
					}
				}
			}

			// None of the provided tags filter match skip the object
			return false
		}

		for _, kv := range r.Flags.Filter.Metadata {
			for k, v := range oi.UserDefined {

app = FastAPI()


class Item(BaseModel):
    name: str
    price: float
    is_offer: Union[bool, None] = None


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


@app.get("/items/{item_id}")
def read_item(item_id: int, q: Union[str, None] = None):
    return {"item_id": item_id, "q": q}


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