from typing import Union

from fastapi import FastAPI
from pydantic import BaseModel

app = FastAPI()


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


@app.post(
    "/items/",
    response_model=Item,
    summary="Create an item",
    response_description="The created item",
)

Agora você sabe que, sempre que precisar delas, pode usá-las no **FastAPI**.

### Pydantic v1 `regex` em vez de `pattern` { #pydantic-v1-regex-instead-of-pattern }

Antes da versão 2 do Pydantic e antes do FastAPI 0.100.0, o parâmetro se chamava `regex` em vez de `pattern`, mas agora está descontinuado.

Você ainda pode ver algum código usando isso:

//// tab | Pydantic v1

from fastapi import FastAPI
from pydantic import BaseModel


class Item(BaseModel):
    name: str
    description: str | None = None
    price: float
    tax: float | None = None


app = FastAPI()


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

from typing import Union

from fastapi import FastAPI, Path
from pydantic import BaseModel

app = FastAPI()


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


@app.put("/items/{item_id}")
async def update_item(
    *,
    item_id: int = Path(title="The ID of the item to get", ge=0, le=1000),
    q: Union[str, None] = None,

import yaml
from fastapi import FastAPI, HTTPException, Request
from pydantic.v1 import BaseModel, ValidationError

app = FastAPI()


class Item(BaseModel):
    name: str
    tags: list[str]


@app.post(
    "/items/",
    openapi_extra={
        "requestBody": {
            "content": {"application/x-yaml": {"schema": Item.schema()}},
            "required": True,
        },
    },
)

import yaml
from fastapi import FastAPI, HTTPException, Request
from pydantic import BaseModel, ValidationError

app = FastAPI()


class Item(BaseModel):
    name: str
    tags: list[str]


@app.post(
    "/items/",
    openapi_extra={
        "requestBody": {
            "content": {"application/x-yaml": {"schema": Item.model_json_schema()}},
            "required": True,
        },
    },
)

* Fix handling of enums with their own schema in path parameters. To support [pydantic/pydantic#1432](https://github.com/pydantic/pydantic/pull/1432) in FastAPI. PR [#1463](https://github.com/tiangolo/fastapi/pull/1463).

## 0.55.0

* Allow enums to allow them to have their own schemas in OpenAPI. To support [pydantic/pydantic#1432](https://github.com/pydantic/pydantic/pull/1432) in FastAPI. PR [#1461](https://github.com/tiangolo/fastapi/pull/1461).

from fastapi import Cookie, FastAPI
from pydantic import BaseModel

app = FastAPI()


class Cookies(BaseModel):
    model_config = {"extra": "forbid"}

    session_id: str
    fatebook_tracker: str | None = None
    googall_tracker: str | None = None


@app.get("/items/")
async def read_items(cookies: Cookies = Cookie()):

from typing import Annotated, Union

from fastapi import Body, FastAPI
from pydantic import BaseModel

app = FastAPI()


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


class User(BaseModel):
    username: str
    full_name: Union[str, None] = None


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

from typing import Annotated

from fastapi import Cookie, FastAPI
from pydantic import BaseModel

app = FastAPI()


class Cookies(BaseModel):
    session_id: str
    fatebook_tracker: str | None = None
    googall_tracker: str | None = None


@app.get("/items/")
async def read_items(cookies: Annotated[Cookies, Cookie()]):