# JSON-kompatibler Encoder { #json-compatible-encoder }

Es gibt Fälle, da möchten Sie einen Datentyp (etwa ein Pydantic-Modell) in etwas konvertieren, das kompatibel mit JSON ist (etwa ein `dict`, eine `list`, usw.).

Zum Beispiel, wenn Sie es in einer Datenbank speichern möchten.

Dafür bietet **FastAPI** eine Funktion `jsonable_encoder()`.

## `jsonable_encoder` verwenden { #using-the-jsonable-encoder }

    data = {"a": 2, "b": "foo"}
    response = client.post(path, json=data)
    assert response.status_code == 200, response.text
    assert data == response.json()


@pytest.mark.parametrize(
    "path", ["/a/compute", "/a/compute/", "/b/compute", "/b/compute/"]
)
def test_post_invalid(path):
    data = {"a": "bar", "b": "foo"}
    response = client.post(path, json=data)
    assert response.status_code == 422, response.text

    assert response.status_code == 200
    assert response.json() == {"foo": "baz"}

    response = client.get("/test2")
    assert response.status_code == 200
    assert response.json() == {"foo": "bar"}

    response = client.get("/test2", params={"var": "baz"})
    assert response.status_code == 200
    assert response.json() == {"foo": "baz"}


def test_nested_router():
    app = FastAPI()

@app.get("/function-scope")
def function_scope(session: SessionFuncDep) -> Any:
    def iter_data():
        yield json.dumps({"is_open": session.open})

    return StreamingResponse(iter_data())


@app.get("/request-scope")
def request_scope(session: SessionRequestDep) -> Any:
    def iter_data():
        yield json.dumps({"is_open": session.open})

    return StreamingResponse(iter_data())


@app.get("/two-scopes")

)

// MarshalText encodes the DEK's key ID and ciphertext
// as JSON.
func (d DEK) MarshalText() ([]byte, error) {
	type JSON struct {
		KeyID      string `json:"keyid"`
		Version    uint32 `json:"version,omitempty"`
		Ciphertext []byte `json:"ciphertext"`
	}
	return json.Marshal(JSON{
		KeyID:      d.KeyID,
		Version:    uint32(d.Version),
		Ciphertext: d.Ciphertext,
	})
}

# JSON Compatible Encoder { #json-compatible-encoder }

There are some cases where you might need to convert a data type (like a Pydantic model) to something compatible with JSON (like a `dict`, `list`, etc).

For example, if you need to store it in a database.

For that, **FastAPI** provides a `jsonable_encoder()` function.

## Using the `jsonable_encoder` { #using-the-jsonable-encoder }

    content = response.json()
    access_token = content.get("access_token")
    return access_token


def test_login(mod: ModuleType):
    client = TestClient(mod.app)
    response = client.post("/token", data={"username": "johndoe", "password": "secret"})
    assert response.status_code == 200, response.text
    content = response.json()
    assert "access_token" in content

{* ../../docs_src/encoder/tutorial001_py310.py hl[4,21] *}

Neste exemplo, ele converteria o modelo Pydantic em um `dict`, e o `datetime` em um `str`.

O resultado de chamar a função é algo que pode ser codificado com o padrão do Python <a href="https://docs.python.org/3/library/json.html#json.dumps" class="external-link" target="_blank">`json.dumps()`</a>.

        },
    )
    assert response.json() == {
        "name": "Fooz",
        "description": "Item description",
        "price": 3,
        "tax": 10.5,
        "tags": ["tag1", "tag2"],
    }


def test_patch_name(client: TestClient):
    response = client.patch(
        "/items/bar",
        json={"name": "Barz"},
    )
    assert response.json() == {
        "name": "Barz",

// V33.
type LegacyConfig struct {
	Enabled bool `json:"enabled"`

	// E.g. "ldap.minio.io:636"
	ServerAddr string `json:"serverAddr"`

	// User DN search parameters
	UserDNSearchBaseDistName  string   `json:"userDNSearchBaseDN"`
	UserDNSearchBaseDistNames []string `json:"-"` // Generated field
	UserDNSearchFilter        string   `json:"userDNSearchFilter"`

	// Group search parameters