response = client.put("/items/5?q=bar", json=None)
    assert response.status_code == 200
    assert response.json() == {"item_id": 5, "q": "bar"}


@needs_py310
def test_post_no_body(client: TestClient):
    response = client.put("/items/5", json=None)
    assert response.status_code == 200
    assert response.json() == {"item_id": 5}


@needs_py310
def test_post_id_foo(client: TestClient):

It doesn't return a large `str` containing the data in JSON format (as a string). It returns a Python standard data structure (e.g. a `dict`) with values and sub-values that are all compatible with JSON.

/// note

    assert response.status_code == 404
    assert response.json() == {"detail": "Item not found"}


def test_create_item():
    response = client.post(
        "/items/",
        headers={"X-Token": "coneofsilence"},
        json={"id": "foobar", "title": "Foo Bar", "description": "The Foo Barters"},
    )
    assert response.status_code == 200
    assert response.json() == {
        "id": "foobar",
        "title": "Foo Bar",

A função não retorna um grande `str` contendo os dados no formato JSON (como uma string). Mas sim, retorna uma estrutura de dados padrão do Python (por exemplo, um `dict`) com valores e subvalores compatíveis com JSON.

/// note | "Nota"

                }
            ]
        }
    )


def test_post_body_json():
    response = client.post("/files/", json={"file": "Foo"})
    assert response.status_code == 422, response.text
    assert response.json() == IsDict(
        {
            "detail": [
                {
                    "type": "missing",
                    "loc": ["body", "files"],

    assert response.status_code == 200
    assert response.json() == {"username": "Foo", "password": "secret"}


@needs_pydanticv2
@needs_py39
def test_post_body_extra_form(client: TestClient):
    response = client.post(
        "/login/", data={"username": "Foo", "password": "secret", "extra": "extra"}
    )
    assert response.status_code == 422
    assert response.json() == {
        "detail": [
            {

    response = client.put("/items/5", json={"item": {"name": "Foo", "price": 3.0}})
    assert response.status_code == 200
    assert response.json() == {
        "item_id": 5,
        "item": {"name": "Foo", "price": 3.0, "description": None, "tax": None},
    }


@needs_py310
def test_items_6(client: TestClient):
    response = client.put(
        "/items/6",
        json={
            "item": {

# JSON 兼容编码器

在某些情况下，您可能需要将数据类型（如Pydantic模型）转换为与JSON兼容的数据类型（如`dict`、`list`等）。

比如，如果您需要将其存储在数据库中。

对于这种要求， **FastAPI**提供了`jsonable_encoder()`函数。

## 使用`jsonable_encoder`

让我们假设你有一个数据库名为`fake_db`，它只能接收与JSON兼容的数据。

例如，它不接收`datetime`这类的对象，因为这些对象与JSON不兼容。

因此，`datetime`对象必须将转换为包含<a href="https://en.wikipedia.org/wiki/ISO_8601" class="external-link" target="_blank">ISO格式化</a>的`str`类型对象。

同样，这个数据库也不会接收Pydantic模型（带有属性的对象），而只接收`dict`。

    response = client.post("/items/", json={"name": "Foo"})
    assert response.status_code == 200, response.text
    assert response.json() == {"name": "Foo", "description": None}


def test_read_items(client: TestClient) -> None:
    response = client.get("/items/")
    assert response.status_code == 200, response.text
    assert response.json() == [
        {
            "name": "Portal Gun",

    response = client.post("/items/", json={"name": "Foo"})
    assert response.status_code == 200, response.text
    assert response.json() == {"name": "Foo", "description": None}


@needs_py39
def test_read_items(client: TestClient) -> None:
    response = client.get("/items/")
    assert response.status_code == 200, response.text
    assert response.json() == [
        {
            "name": "Portal Gun",