## 检查

现在，所有定义在 `/v1/` 路径下的请求将会被 Flask 应用处理。

其余的请求则会被 **FastAPI** 处理。

如果您使用 Uvicorn 运行应用实例并且访问 <a href="http://localhost:8000/v1/" class="external-link" target="_blank">http://localhost:8000/v1/</a>，您将会看到由 Flask 返回的响应：

```txt
Hello, World from Flask!
```

并且如果您访问 <a href="http://localhost:8000/v2" class="external-link" target="_blank">http://localhost:8000/v2</a>，您将会看到由 FastAPI 返回的响应：

```JSON
{
    "message": "Hello World"
}

# 请求表单与文件

FastAPI 支持同时使用 `File` 和 `Form` 定义文件和表单字段。

/// info | "说明"

接收上传文件或表单数据，要预先安装 <a href="https://github.com/Kludex/python-multipart" class="external-link" target="_blank">`python-multipart`</a>。

例如，`pip install python-multipart`。

///

## 导入 `File` 与 `Form`

```Python hl_lines="1"
{!../../docs_src/request_forms_and_files/tutorial001.py!}
```

## 定义 `File` 与 `Form` 参数

创建文件和表单参数的方式与 `Body` 和 `Query` 一样：

import pytest
from dirty_equals import IsDict
from fastapi.testclient import TestClient

from docs_src.cookie_params.tutorial001 import app


@pytest.mark.parametrize(
    "path,cookies,expected_status,expected_response",
    [
        ("/items", None, 200, {"ads_id": None}),
        ("/items", {"ads_id": "ads_track"}, 200, {"ads_id": "ads_track"}),
        (
            "/items",
            {"ads_id": "ads_track", "session": "cookiesession"},

import pytest
from dirty_equals import IsDict
from fastapi.testclient import TestClient

from docs_src.header_params.tutorial003 import app

client = TestClient(app)


@pytest.mark.parametrize(
    "path,headers,expected_status,expected_response",
    [
        ("/items", None, 200, {"X-Token values": None}),
        ("/items", {"x-token": "foo"}, 200, {"X-Token values": ["foo"]}),
        (
            "/items",

import pytest
from fastapi.testclient import TestClient

from ...utils import needs_py39


@pytest.fixture(name="client")
def get_client():
    from docs_src.query_params_str_validations.tutorial012_an_py39 import app

    client = TestClient(app)
    return client


@needs_py39
def test_default_query_values(client: TestClient):
    url = "/items/"
    response = client.get(url)

from typing import List

from fastapi import FastAPI, File, UploadFile
from fastapi.responses import HTMLResponse

app = FastAPI()


@app.post("/files/")
async def create_files(
    files: List[bytes] = File(description="Multiple files as bytes"),
):
    return {"file_sizes": [len(file) for file in files]}


@app.post("/uploadfiles/")
async def create_upload_files(

from typing import List

from fastapi import FastAPI, File, UploadFile
from fastapi.responses import HTMLResponse
from typing_extensions import Annotated

app = FastAPI()


@app.post("/files/")
async def create_files(
    files: Annotated[List[bytes], File(description="Multiple files as bytes")],
):
    return {"file_sizes": [len(file) for file in files]}


@app.post("/uploadfiles/")
async def create_upload_files(

from typing import Annotated

from fastapi import Body, FastAPI
from pydantic import BaseModel

app = FastAPI()


class Item(BaseModel):
    name: str
    description: str | None = None
    price: float
    tax: float | None = None


@app.put("/items/{item_id}")
async def update_item(
    *,
    item_id: int,
    item: Annotated[
        Item,
        Body(
            openapi_examples={

from fastapi.encoders import jsonable_encoder
from fastapi.exceptions import RequestValidationError, WebSocketRequestValidationError
from fastapi.utils import is_body_allowed_for_status_code
from fastapi.websockets import WebSocket
from starlette.exceptions import HTTPException
from starlette.requests import Request
from starlette.responses import JSONResponse, Response
from starlette.status import HTTP_422_UNPROCESSABLE_ENTITY, WS_1008_POLICY_VIOLATION

Yani yumurta mı tavukdan, tavuk mu yumurtadan gibi ilk `async` fonksiyonu nasıl çağırılır?

**FastAPI** ile çalışıyorsanız bunun için endişelenmenize gerek yok, çünkü bu "ilk" fonksiyon sizin *path fonksiyonunuz* olacak ve FastAPI doğru olanı nasıl yapacağını bilecek.