/// danger | Gefahr

Dies ist eine „fortgeschrittene“ Funktion.

Wenn Sie gerade erst mit **FastAPI** beginnen, möchten Sie diesen Abschnitt vielleicht überspringen.

///

## Anwendungsfälle { #use-cases }

Einige Anwendungsfälle sind:

# 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`。

import importlib

import pytest
from fastapi.testclient import TestClient

from ...utils import needs_py310


@pytest.fixture(
    name="client",
    params=[
        pytest.param("tutorial004_py39"),
        pytest.param("tutorial004_py310", marks=needs_py310),
    ],
)
def get_client(request: pytest.FixtureRequest):
    mod = importlib.import_module(f"docs_src.body.{request.param}")

    client = TestClient(mod.app)

import importlib

import pytest
from fastapi.testclient import TestClient

from ...utils import needs_py310


@pytest.fixture(
    name="client",
    params=[
        pytest.param("tutorial002_py39"),
        pytest.param("tutorial002_py310", marks=needs_py310),
        pytest.param("tutorial002_an_py39"),
        pytest.param("tutorial002_an_py310", marks=needs_py310),
        pytest.param("tutorial003_py39"),

import importlib
from types import ModuleType

import pytest
from fastapi.testclient import TestClient

from ...utils import needs_py310


@pytest.fixture(
    name="mod",
    params=[
        pytest.param("tutorial001_py39"),
        pytest.param("tutorial001_py310", marks=needs_py310),
    ],
)
def get_module(request: pytest.FixtureRequest):
    module = importlib.import_module(f"docs_src.encoder.{request.param}")

import importlib

import pytest
from fastapi.testclient import TestClient


@pytest.fixture(
    name="client",
    params=[
        pytest.param("tutorial004_py39"),
        pytest.param("tutorial004_an_py39"),
    ],
)
def get_client(request: pytest.FixtureRequest) -> TestClient:
    mod = importlib.import_module(
        f"docs_src.path_params_numeric_validations.{request.param}"
    )
    return TestClient(mod.app)

import importlib

import pytest
from fastapi.testclient import TestClient


@pytest.fixture(
    name="client",
    params=[
        "tutorial001_py39",
        "tutorial001_an_py39",
    ],
)
def get_client(request: pytest.FixtureRequest):
    mod = importlib.import_module(f"docs_src.request_form_models.{request.param}")

    client = TestClient(mod.app)
    return client


def test_post_body_form(client: TestClient):

import importlib

import pytest
from fastapi.testclient import TestClient


@pytest.fixture(
    name="client",
    params=[
        "tutorial001_py39",
        "tutorial001_an_py39",
    ],
)
def get_client(request: pytest.FixtureRequest):
    mod = importlib.import_module(f"docs_src.request_forms.{request.param}")

    client = TestClient(mod.app)
    return client


def test_post_body_form(client: TestClient):

{* ../../docs_src/static_files/tutorial001_py39.py hl[2,6] *}

/// note | Detalhes Técnicos

Você também pode usar `from starlette.staticfiles import StaticFiles`.

O **FastAPI** fornece o mesmo que `starlette.staticfiles` como `fastapi.staticfiles` apenas como uma conveniência para você, o desenvolvedor. Mas na verdade vem diretamente da Starlette.

///

### O que é "Montagem" { #what-is-mounting }

# 關於 FastAPI