from fastapi import FastAPI

app = FastAPI()


@app.get("/items/")
async def read_items(q: str | None = None):
    results = {"items": [{"item_id": "Foo"}, {"item_id": "Bar"}]}
    if q:
        results.update({"q": q})

        title=app.title + " - ReDoc",
        redoc_js_url="https://unpkg.com/redoc@2/bundles/redoc.standalone.js",
    )


@app.get("/users/{username}")
async def read_user(username: str):

    client = TestClient(app)
    return client


@pytest.mark.parametrize("client", [True, False], indirect=True)
@pytest.mark.parametrize("path", ["/", "/responses"])
def test_get(client: TestClient, path: str):
    response = client.get(path)
    assert response.status_code == 200, response.text
    assert response.json() == {"width": 3, "length": 4, "area": 12}


@pytest.mark.parametrize("client", [True, False], indirect=True)

from fastapi import FastAPI, Query

app = FastAPI()


@app.get("/items/")
async def read_items(
    hidden_query: str | None = Query(default=None, include_in_schema=False),
):
    if hidden_query:
        return {"hidden_query": hidden_query}
    else:

from fastapi import FastAPI, Path, Query

app = FastAPI()


@app.get("/items/{item_id}")
async def read_items(
    item_id: Annotated[int, Path(title="The ID of the item to get")],
    q: Annotated[str | None, Query(alias="item-query")] = None,
):
    results = {"item_id": item_id}
    if q:
        results.update({"q": q})

from fastapi import FastAPI, Query

app = FastAPI()


@app.get("/items/")
async def read_items(q: str = Query(min_length=3)):
    results = {"items": [{"item_id": "Foo"}, {"item_id": "Bar"}]}
    if q:
        results.update({"q": q})

from fastapi import FastAPI, File, Form, UploadFile

app = FastAPI()


@app.post("/files/")
async def create_file(
    file: bytes = File(), fileb: UploadFile = File(), token: str = Form()
):
    return {
        "file_size": len(file),
        "token": token,
        "fileb_content_type": fileb.content_type,

from functools import partial

from fastapi import FastAPI
from fastapi.testclient import TestClient


def main(some_arg, q: str | None = None):
    return {"some_arg": some_arg, "q": q}


endpoint = partial(main, "foo")

app = FastAPI()

app.get("/")(endpoint)


client = TestClient(app)


def test_partial():
    response = client.get("/?q=bar")
    data = response.json()

app = FastAPI()


class FilterParams(BaseModel):
    limit: int = Field(100, gt=0, le=100)
    offset: int = Field(0, ge=0)
    order_by: Literal["created_at", "updated_at"] = "created_at"
    tags: list[str] = []


@app.get("/items/")
async def read_items(filter_query: FilterParams = Query()):

Your response model could have default values, like:

{* ../../docs_src/response_model/tutorial004_py310.py hl[9,11:12] *}

* `description: Union[str, None] = None` (or `str | None = None` in Python 3.10) has a default of `None`.
* `tax: float = 10.5` has a default of `10.5`.
* `tags: List[str] = []` has a default of an empty list: `[]`.

but you might want to omit them from the result if they were not actually stored.