运行示例并访问 <a href="http://127.0.0.1:8000/items/3" class="external-link" target="_blank">http://127.0.0.1:8000/items/3</a>，返回的响应如下：

```JSON
{"item_id":3}
```

/// check | "检查"

注意，函数接收并返回的值是 `3`（ `int`），不是 `"3"`（`str`）。

**FastAPI** 通过类型声明自动<abbr title="将来自 HTTP 请求中的字符串转换为 Python 数据类型">**解析**请求中的数据</abbr>。

///

## 数据校验

                "GRADLE_RUNNER",
                "KILL_PROCESSES_STARTED_BY_GRADLE",
                "CHECK_CLEAN_M2_ANDROID_USER_HOME"
            ),
            steps.items.map(BuildStep::name)
        )
        assertEquals(expectedRunnerParam(), steps.getGradleStep("GRADLE_RUNNER").gradleParams)
    }

    @ParameterizedTest
    @CsvSource(
        value = [

from typing import Annotated

from fastapi import FastAPI, Query

app = FastAPI()


@app.get("/items/")
async def read_items(q: Annotated[str, Query(min_length=3)]):
    results = {"items": [{"item_id": "Foo"}, {"item_id": "Bar"}]}
    if q:
        results.update({"q": q})

from fastapi import FastAPI, Query
from typing_extensions import Annotated

app = FastAPI()


@app.get("/items/")
async def read_items(q: Annotated[str, Query(min_length=3)] = ...):
    results = {"items": [{"item_id": "Foo"}, {"item_id": "Bar"}]}
    if q:
        results.update({"q": q})

                    "title": "Body_post_form_form__post",
                },
                "HTTPValidationError": {
                    "properties": {
                        "detail": {
                            "items": {"$ref": "#/components/schemas/ValidationError"},
                            "type": "array",
                            "title": "Detail",
                        }
                    },

                        "properties": {
                            "detail": {
                                "title": "Detail",
                                "type": "array",
                                "items": {
                                    "$ref": "#/components/schemas/ValidationError"
                                },
                            }
                        },
                    },

                    "properties": {
                        "detail": {
                            "title": "Detail",
                            "type": "array",
                            "items": {"$ref": "#/components/schemas/ValidationError"},
                        }
                    },
                },
                "ValidationError": {
                    "title": "ValidationError",

                    "properties": {
                        "detail": {
                            "title": "Detail",
                            "type": "array",
                            "items": {"$ref": "#/components/schemas/ValidationError"},
                        }
                    },
                },
                "ValidationError": {
                    "title": "ValidationError",

                    "properties": {
                        "files": {
                            "title": "Files",
                            "type": "array",
                            "items": {"type": "string", "format": "binary"},
                        }
                    },
                },
                "Body_create_files_files__post": {

pwd_context = CryptContext(schemes=["bcrypt"], deprecated="auto")

oauth2_scheme = OAuth2PasswordBearer(
    tokenUrl="token",
    scopes={"me": "Read information about the current user.", "items": "Read items."},
)

app = FastAPI()


def verify_password(plain_password, hashed_password):
    return pwd_context.verify(plain_password, hashed_password)


def get_password_hash(password):