Ihr Responsemodell könnte Defaultwerte haben, wie:

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

* `description: Union[str, None] = None` (oder `str | None = None` in Python 3.10) hat einen Defaultwert `None`.
* `tax: float = 10.5` hat einen Defaultwert `10.5`.
* `tags: List[str] = []` hat eine leere Liste als Defaultwert: `[]`.

                .name("defaultDispatcher")
                .message("Which dispatcher you want to use as default?");
        listPromptBuilder
                .newItem()
                .name(NONE)
                .text("None (disable MavenSecDispatcher)")
                .add();
        for (DispatcherMeta meta : secDispatcher.availableDispatchers()) {
            if (!meta.isHidden()) {
                listPromptBuilder

{* ../../docs_src/metadata/tutorial002.py hl[3] *}

如果你想完全禁用 OpenAPI 模式，可以将其设置为 `openapi_url=None`，这样也会禁用使用它的文档用户界面。

## 文档 URLs

你可以配置两个文档用户界面，包括：

* **Swagger UI**：服务于 `/docs`。
    * 可以使用参数 `docs_url` 设置它的 URL。
    * 可以通过设置 `docs_url=None` 禁用它。
* ReDoc：服务于 `/redoc`。
    * 可以使用参数 `redoc_url` 设置它的 URL。
    * 可以通过设置 `redoc_url=None` 禁用它。

例如，设置 Swagger UI 服务于 `/documentation` 并禁用 ReDoc：

     * Gets the installation Toolchains source.
     *
     * @return the installation Toolchains source or {@code null} if none
     */
    @Nonnull
    Optional<Source> getInstallationToolchainsSource();

    /**
     * Gets the user Toolchains source.
     *
     * @return the user Toolchains source or {@code null} if none
     */
    @Nonnull
    Optional<Source> getUserToolchainsSource();

    @Nonnull

    /**
     * Locates the pom in the given directory.
     *
     * @param dir the directory to locate the pom for, never {@code null}
     * @return a {@code Source} pointing to the located pom or an empty {@code Optional} if none was found by this parser
     */
    @Nonnull
    Optional<Source> locate(@Nonnull Path dir);

    /**
     * Parse the model obtained previously by a previous call to {@link #locate(Path)}.
     *

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):
    return {"item_id": item_id, "q": q}


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

`id` der **Primärschlüssel** in der SQL-Datenbank ist (Sie können mehr über SQL-Primärschlüssel in der SQLModel-Dokumentation erfahren).

    **Hinweis:** Wir verwenden für das Primärschlüsselfeld `int | None`, damit wir im Python-Code *ein Objekt ohne `id` erstellen* können (`id=None`), in der Annahme, dass die Datenbank sie *beim Speichern generiert*. SQLModel versteht, dass die Datenbank die `id` bereitstellt, und *definiert die Spalte im Datenbankschema als ein Nicht-Null-`INTEGER`*. Siehe...

                DependencyScope.TEST.isTransitive(),
                byProjectPath(CommonBuilds.PROJECT_PATH_TEST)));
        result.add(internalScopeManager.createDependencyScope(
                DependencyScope.NONE.id(), DependencyScope.NONE.isTransitive(), Collections.emptySet()));
        result.add(internalScopeManager.createDependencyScope(
                DependencyScope.COMPILE_ONLY.id(),
                DependencyScope.COMPILE_ONLY.isTransitive(),

    )
    assert response.status_code == 200
    assert response.json() == {
        "item_id": 123,
        "name": "Foo",
        "price": 50.1,
        "description": None,
        "tax": None,
    }


def test_put_with_no_data(client: TestClient):
    response = client.put("/items/123", json={})
    assert response.status_code == 422
    assert response.json() == {
        "detail": [

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):
    return {"item_id": item_id, "q": q}


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