而且很多情况下，读取它们是一个阻塞操作（可能会阻塞事件循环），因为数据来自磁盘或网络。

/// info | 信息

上面的示例其实是个例外，因为 `io.BytesIO` 对象已经在内存中，所以读取它不会阻塞。

但在许多情况下，读取文件或类文件对象会发生阻塞。

///

为避免阻塞事件循环，你可以简单地把*路径操作函数*声明为常规的 `def`（而不是 `async def`），这样 FastAPI 会在一个线程池工作线程上运行它，从而避免阻塞主事件循环。

{* ../../docs_src/stream_data/tutorial002_py310.py ln[30:34] hl[31] *}

/// tip | 提示

class Item(BaseModel):
    name: str
    description: str | None = None
    price: float
    tax: float | None = None
    tags: set[str] = set()


@app.post("/items/", summary="Create an item")
async def create_item(item: Item) -> Item:
    """
    Create an item with all the information:

    - **name**: each item must have a name
    - **description**: a long description
    - **price**: required

        aws_access_key_id='YOUR-ACCESSKEYID',
        aws_secret_access_key='YOUR-SECRETACCESSKEY',
        config=Config(signature_version='s3v4'),
        region_name='us-east-1')


def _add_header(request, **kwargs):
    request.headers.add_header('x-minio-extract', 'true')
event_system = s3.meta.events
event_system.register_first('before-sign.s3.*', _add_header)

# List zip contents

 * Side Public License, v 1.
 */

import org.elasticsearch.gradle.Version
import org.elasticsearch.gradle.internal.info.BuildParams

ext.bwcTaskName = { Version version ->
  return "v${version}#bwcTest"
}

def bwcTestSnapshots = tasks.register("bwcTestSnapshots") {
  if (project.bwc_tests_enabled) {
    dependsOn tasks.matching { task -> BuildParams.bwcVersions.unreleased.any { version -> bwcTaskName(version) == task.name } }
  }
}

import org.junit.rules.TemporaryFolder

abstract class AbstractGitAwareGradleFuncTest extends AbstractGradleFuncTest {

    @Rule
    TemporaryFolder remoteRepoDirs = new TemporaryFolder()

    File remoteGitRepo

    def setup() {
        remoteGitRepo = new File(setupGitRemote(), '.git')
        "git clone ${remoteGitRepo.absolutePath} cloned".execute(Collections.emptyList(), testProjectDir.root).waitFor()

# Code blocks { #code-blocks }

Some text

```python
# This is a sample Python code block
def hello_world():
    # Comment with indentation
    print("Hello, world!")  # Print greeting
```

Some more text

```toml
# Extra line
# This is a sample TOML code block
title = "TOML Example"  # Title of the document
```

And more text

```console
// Use the command "live" and pass the language code as a CLI argument

        "email": "******@****.***",
    },
    license_info={
        "name": "Apache 2.0",
        "url": "https://www.apache.org/licenses/LICENSE-2.0.html",
    },
)


@app.get("/items/")
async def read_items():

    github_repository: str
    github_token: SecretStr


class Repo(BaseModel):
    name: str
    html_url: str
    stars: int
    owner_login: str
    owner_html_url: str


def main() -> None:
    logging.basicConfig(level=logging.INFO)
    settings = Settings()

    logging.info(f"Using config: {settings.model_dump_json()}")
    g = Github(settings.github_token.get_secret_value(), per_page=100)

        .isEqualTo("\uD8AB\uDCABdef");
    // Differing valid surrogate pairs.
    assertThat(Strings.commonSuffix("abc\uD8AB\uDCABdef", "abc\uD8AC\uDCABdef")).isEqualTo("def");
    // One invalid pair.
    assertThat(Strings.commonSuffix("abc\uD8AB\uDCABdef", "xyz\uDCAB\uDCABdef")).isEqualTo("def");
    // Two identical invalid pairs.
    assertThat(Strings.commonSuffix("abc\uD8AB\uD8ABdef", "xyz\uD8AB\uD8ABdef"))
        .isEqualTo("\uD8AB\uD8ABdef");

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={
                "normal": {
                    "summary": "A normal example",