@app.get(
    "/response_model_union-no_annotation-return_model1",
    response_model=Union[User, Item],
)
def response_model_union_no_annotation_return_model1():
    return DBUser(name="John", surname="Doe", password_hash="secret")


@app.get(
    "/response_model_union-no_annotation-return_model2",
    response_model=Union[User, Item],
)
def response_model_union_no_annotation_return_model2():

from typing import Any, List, 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: List[str] = []


@app.post("/items/", response_model=Item)
async def create_item(item: Item) -> Any:
    return item


@app.get("/items/", response_model=List[Item])

from typing import Set, 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, tags=["items"])
async def create_item(item: Item):
    return item


@app.get("/items/", tags=["items"])

class Token(BaseModel):
    access_token: str
    token_type: str


class TokenData(BaseModel):
    username: Union[str, None] = None
    scopes: List[str] = []


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


class UserInDB(User):
    hashed_password: str

from typing import List, Union

from fastapi import Depends, FastAPI, HTTPException, Query
from sqlmodel import Field, Session, SQLModel, create_engine, select


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


sqlite_file_name = "database.db"

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")
async def create_item(item: Item):
    """
    Create an item with all the information:

Le paramètre de requête `q` a pour type `Union[str, None]` (ou `str | None` en Python 3.10), signifiant qu'il est de type `str` mais pourrait aussi être égal à `None`, et bien sûr, la valeur par défaut est `None`, donc **FastAPI** saura qu'il n'est pas requis.

/// note

**FastAPI** saura que la valeur de `q` n'est pas requise grâce à la valeur par défaut `= None`.

        @app.get("/query_example/")
        def query_example(
            data: Union[str, None] = Query(
                default=None,
                example="query1",
            ),
        ):
            return data

    @app.get("/query_examples/")
    def query_examples(
        data: Union[str, None] = Query(
            default=None,
            examples=["query1", "query2"],
        ),

from typing import List, Union

from fastapi import Depends, FastAPI, HTTPException, Query
from sqlmodel import Field, Session, SQLModel, create_engine, select
from typing_extensions import Annotated


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

from typing import Union

from fastapi import FastAPI, Header
from typing_extensions import Annotated

app = FastAPI()


@app.get("/items/")
async def read_items(user_agent: Annotated[Union[str, None], Header()] = None):