from typing import Annotated, Union

from fastapi import FastAPI, Header
from pydantic import BaseModel

app = FastAPI()


class CommonHeaders(BaseModel):
    host: str
    save_data: bool
    if_modified_since: Union[str, None] = None
    traceparent: Union[str, None] = None
    x_tag: list[str] = []


@app.get("/items/")
async def read_items(headers: Annotated[CommonHeaders, Header()]):

/// check | "Remarque"

On peut voir que **FastAPI** est capable de détecter que le paramètre de chemin `item_id` est un paramètre de chemin et que `q` n'en est pas un, c'est donc un paramètre de requête.

///

/// note

**FastAPI** saura que `q` est optionnel grâce au `=None`.

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: list = []


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

from typing import List, Union

from fastapi import FastAPI, Header
from pydantic import BaseModel

app = FastAPI()


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

    host: str
    save_data: bool
    if_modified_since: Union[str, None] = None
    traceparent: Union[str, None] = None
    x_tag: List[str] = []


@app.get("/items/")
async def read_items(headers: CommonHeaders = Header()):

from typing import List, Union

from fastapi import FastAPI, Header
from pydantic import BaseModel

app = FastAPI()


class CommonHeaders(BaseModel):
    class Config:
        extra = "forbid"

    host: str
    save_data: bool
    if_modified_since: Union[str, None] = None
    traceparent: Union[str, None] = None
    x_tag: List[str] = []


@app.get("/items/")
async def read_items(headers: CommonHeaders = Header()):

from typing import Union

from fastapi import FastAPI, Header
from pydantic import BaseModel

app = FastAPI()


class CommonHeaders(BaseModel):
    class Config:
        extra = "forbid"

    host: str
    save_data: bool
    if_modified_since: Union[str, None] = None
    traceparent: Union[str, None] = None
    x_tag: list[str] = []


@app.get("/items/")
async def read_items(headers: CommonHeaders = Header()):

/// info

À moins que vous ne spécifiiez explicitement un type de média différent dans votre paramètre `responses`, FastAPI supposera que la réponse a le même type de média que la classe de réponse principale (par défaut `application/json`).

Mais si vous avez spécifié une classe de réponse personnalisée avec `None` comme type de média, FastAPI utilisera `application/json` pour toute réponse supplémentaire associée à un modèle.

///

from typing import Dict, List, Tuple

import pytest
from fastapi import FastAPI
from pydantic import BaseModel


def test_invalid_sequence():
    with pytest.raises(AssertionError):
        app = FastAPI()

        class Item(BaseModel):
            title: str

        @app.get("/items/{id}")
        def read_items(id: List[Item]):
            pass  # pragma: no cover


def test_invalid_tuple():

from fastapi.testclient import TestClient

from docs_src.header_params.tutorial001_an import app

client = TestClient(app)


@pytest.mark.parametrize(
    "path,headers,expected_status,expected_response",
    [
        ("/items", None, 200, {"User-Agent": "testclient"}),
        ("/items", {"X-Header": "notvalid"}, 200, {"User-Agent": "testclient"}),

And it will be documented as such in OpenAPI.

///

/// tip

The `ORJSONResponse` is only available in FastAPI, not in Starlette.

///

## HTML Response

To return a response with HTML directly from **FastAPI**, use `HTMLResponse`.

* Import `HTMLResponse`.
* Pass `HTMLResponse` as the parameter `response_class` of your *path operation decorator*.