В данном случае это асинхронная (`async`) функция.

---

Вы также можете определить её как обычную функцию вместо `async def`:

{* ../../docs_src/first_steps/tutorial003_py39.py hl[7] *}

/// note | Примечание

Если вы не знаете, в чём разница, посмотрите [Асинхронность: *"Нет времени?"*](../async.md#in-a-hurry){.internal-link target=_blank}.

///

这是一个 Python 函数。

每当 **FastAPI** 接收一个使用 `GET` 方法访问 URL「`/`」的请求时这个函数会被调用。

在这个例子中，它是一个 `async` 函数。

---

你也可以将其定义为常规函数而不使用 `async def`:

{* ../../docs_src/first_steps/tutorial003.py hl[7] *}

/// note

如果你不知道两者的区别，请查阅 [并发: *赶时间吗？*](../async.md#_1){.internal-link target=_blank}。

///

### 步骤 5：返回内容

{* ../../docs_src/first_steps/tutorial001.py hl[8] *}

// along with this program.  If not, see <http://www.gnu.org/licenses/>.

// Package deadlineconn implements net.Conn wrapper with configured deadlines.
package deadlineconn

import (
	"context"
	"net"
	"sync"
	"sync/atomic"
	"time"
)

// updateInterval is the minimum time between deadline updates.
const updateInterval = 250 * time.Millisecond

package ioutil

import (
	"io"
	"os"

	"github.com/minio/minio/internal/lock"
)

// AppendFile - appends the file "src" to the file "dst"
func AppendFile(dst string, src string, osync bool) error {
	appendFile, err := lock.Open(dst, os.O_WRONLY|os.O_APPEND|os.O_CREATE, 0o666)
	if err != nil {
		return err
	}
	defer appendFile.Close()

	srcFile, err := lock.Open(src, os.O_RDONLY, 0o666)

package stmt_store

import (
	"context"
	"database/sql"
	"math"
	"sync"
	"time"

	"gorm.io/gorm/internal/lru"
)

type Stmt struct {
	*sql.Stmt
	Transaction bool
	prepared    chan struct{}
	prepareErr  error
}

func (stmt *Stmt) Error() error {
	return stmt.prepareErr
}

func (stmt *Stmt) Close() error {
	<-stmt.prepared

	if stmt.Stmt != nil {
		return stmt.Stmt.Close()
	}
	return nil

        """
        return HTTPException(
            status_code=HTTP_401_UNAUTHORIZED,
            detail="Not authenticated",
            headers={"WWW-Authenticate": "Bearer"},
        )

    async def __call__(self, request: Request) -> Optional[str]:
        authorization = request.headers.get("Authorization")
        if not authorization:
            if self.auto_error:

//go:build unix

package tar

import (
	"io/fs"
	"os/user"
	"runtime"
	"strconv"
	"sync"
	"syscall"
)

func init() {
	sysStat = statUnix
}

// userMap and groupMap caches UID and GID lookups for performance reasons.
// The downside is that renaming uname or gname by the OS never takes effect.
var userMap, groupMap sync.Map // map[int]string

func statUnix(fi fs.FileInfo, h *Header, doNameLookups bool) error {

package kafka

import (
	"context"
	"crypto/tls"
	"crypto/x509"
	"encoding/json"
	"errors"
	"fmt"
	"log"
	"os"
	"path/filepath"
	"sync"
	"sync/atomic"
	"time"

	"github.com/IBM/sarama"
	saramatls "github.com/IBM/sarama/tools/tls"

	xioutil "github.com/minio/minio/internal/ioutil"
	types "github.com/minio/minio/internal/logger/target/loggertypes"

// along with this program.  If not, see <http://www.gnu.org/licenses/>.

package dsync

import (
	"math/rand"
	"sync"
)

// lockedRandSource provides protected rand source, implements rand.Source interface.
type lockedRandSource struct {
	lk  sync.Mutex
	src rand.Source
}

// Int63 returns a non-negative pseudo-random 63-bit integer as an int64.

    async def app(scope: Scope, receive: Receive, send: Send) -> None:
        session = WebSocket(scope, receive=receive, send=send)

        async def app(scope: Scope, receive: Receive, send: Send) -> None:
            async with AsyncExitStack() as request_stack:
                scope["fastapi_inner_astack"] = request_stack
                async with AsyncExitStack() as function_stack: