pour débutants avancés pour compléter cette section de la documentation, vous pouvez consulter : <a href="https://testdrive.io/courses/tdd-fastapi/" class="external- link" target="_blank">Développement piloté par les tests avec FastAPI et Docker</a> par **TestDriven.io**.

10 % de tous les bénéfices de ce cours sont reversés au développement de **FastAPI**. 🎉 😄...

from typing import Union

from fastapi import FastAPI
from fastapi.responses import FileResponse
from pydantic import BaseModel


class Item(BaseModel):
    id: str
    value: str


app = FastAPI()


@app.get(
    "/items/{item_id}",
    response_model=Item,
    responses={
        200: {
            "content": {"image/png": {}},
            "description": "Return the JSON item or an image.",
        }
    },

Read more about it in the [FastAPI docs for Custom Response - HTML, Stream, File, others](https://fastapi.tiangolo.com/advanced/custom-response/).

You can import them directly from `fastapi.responses`:

```python
from fastapi.responses import (
    FileResponse,
    HTMLResponse,
    JSONResponse,
    ORJSONResponse,
    PlainTextResponse,

from fastapi import FastAPI
from fastapi.testclient import TestClient

from .utils import needs_py310


@needs_py310
def test_typing():
    types = {
        list[int]: [1, 2, 3],
        dict[str, list[int]]: {"a": [1, 2, 3], "b": [4, 5, 6]},
        set[int]: [1, 2, 3],  # `set` is converted to `list`
        tuple[int, ...]: [1, 2, 3],  # `tuple` is converted to `list`
    }
    for test_type, expect in types.items():

并从以下对象中提取数据：

* 路径参数
* 请求头
* Cookies
* 等

**FastAPI** 使用这种方式验证数据、转换数据，并自动生成 API 文档。

但有时，我们也需要直接访问 `Request` 对象。

## `Request` 对象的细节

实际上，**FastAPI** 的底层是 **Starlette**，**FastAPI** 只不过是在  **Starlette** 顶层提供了一些工具，所以能直接使用 Starlette 的  <a href="https://www.starlette.dev/requests/" class="external-link" target="_blank">`Request`</a> 对象。

但直接从 `Request` 对象提取数据时（例如，读取请求体），**FastAPI** 不会验证、转换和存档数据（为 API 文档使用 OpenAPI）。

from base64 import b64encode
from typing import Optional

from fastapi import FastAPI, Security
from fastapi.security import HTTPBasic, HTTPBasicCredentials
from fastapi.testclient import TestClient

app = FastAPI()

security = HTTPBasic(auto_error=False)


@app.get("/users/me")
def read_current_user(credentials: Optional[HTTPBasicCredentials] = Security(security)):
    if credentials is None:

from typing import Annotated

import pytest
from fastapi import Depends, FastAPI, Path
from fastapi.param_functions import Query
from fastapi.testclient import TestClient

app = FastAPI()


def test_no_annotated_defaults():
    with pytest.raises(
        AssertionError, match="Path parameters cannot have a default value"
    ):

        @app.get("/items/{item_id}/")
        async def get_item(item_id: Annotated[int, Path(default=1)]):

**FastAPI** предоставляет `fastapi.responses`, которые являются теми же объектами, что и `starlette.responses`, просто для удобства. Однако большинство доступных типов ответов поступает непосредственно из **Starlette**.

И так как `Response` часто используется для установки HTTP-заголовков и cookies, **FastAPI** также предоставляет его как `fastapi.Response`.

///

from typing import Union

from fastapi import FastAPI
from fastapi.responses import FileResponse
from pydantic import BaseModel


class Item(BaseModel):
    id: str
    value: str


responses = {
    404: {"description": "Item not found"},
    302: {"description": "The item was moved"},
    403: {"description": "Not enough privileges"},
}


app = FastAPI()


@app.get(
    "/items/{item_id}",

    for example the URLs to use to load Swagger UI's JavaScript and CSS.

    Read more about it in the
    [FastAPI docs for Configure Swagger UI](https://fastapi.tiangolo.com/how-to/configure-swagger-ui/)
    and the [FastAPI docs for Custom Docs UI Static Assets (Self-Hosting)](https://fastapi.tiangolo.com/how-to/custom-docs-ui-assets/).
    """
    current_swagger_ui_parameters = swagger_ui_default_parameters.copy()