```Python hl_lines="4  9-12  25-27"
from typing import Union

from fastapi import FastAPI
from pydantic import BaseModel

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):

```Python hl_lines="4  9-12  25-27"
from typing import Union

from fastapi import FastAPI
from pydantic import BaseModel

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):

```Python hl_lines="4  9-12  25-27"
from typing import Union

from fastapi import FastAPI
from pydantic import BaseModel

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):

```Python hl_lines="4  9-12  25-27"
from typing import Union

from fastapi import FastAPI
from pydantic import BaseModel

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):

```Python hl_lines="4  9-12  25-27"
from typing import Union

from fastapi import FastAPI
from pydantic import BaseModel

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):

### Предупреждение о замене

Это означает, что если вы хотите обновить элемент `bar`, используя `PUT` с телом, содержащим:

```Python
{
    "name": "Barz",
    "price": 3,
    "description": None,
}
```

поскольку оно не включает уже сохраненный атрибут `"tax": 20.2`, входная модель примет значение по умолчанию `"tax": 10.5`.

        urlFilter.addInclude("https://example\\.com/\\?.*");
        urlFilter.addInclude(".*\\$price=\\d+.*");
        urlFilter.addExclude(".*\\[\\].*");

        assertTrue(urlFilter.match("https://example.com/?page=1"));
        assertTrue(urlFilter.match("https://shop.com/item?$price=100"));
        assertFalse(urlFilter.match("https://example.com/array[]"));
    }

    /**

 * @author ******@****.*** (Geoff Pike)
 */
final class Fingerprint2011 extends AbstractNonStreamingHashFunction {
  static final HashFunction FINGERPRINT_2011 = new Fingerprint2011();

  // Some primes between 2^63 and 2^64 for various uses.
  private static final long K0 = 0xa5b85c5e198ed849L;
  private static final long K1 = 0x8d58ac26afe12e47L;
  private static final long K2 = 0xc47b6e9e3a970ed3L;

Por ejemplo, aunque `users` iría después de `items` en orden alfabético, se muestra antes porque agregamos su metadata como el primer diccionario en la list.

## URL de OpenAPI

Por defecto, el esquema OpenAPI se sirve en `/openapi.json`.

Pero puedes configurarlo con el parámetro `openapi_url`.

```Python hl_lines="4  9-12  25-27"
from typing import Union

from fastapi import FastAPI
from pydantic import BaseModel

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):