// the file from concurrent access across mount points.
// This implementation doesn't support all the open
// flags and shouldn't be considered as replacement
// for os.OpenFile().
func LockedOpenFile(path string, flag int, perm os.FileMode) (*LockedFile, error) {
	return lockedOpenFile(path, flag, perm, 0)
}

// Open - Call os.OpenFile
func Open(path string, flag int, perm os.FileMode) (*os.File, error) {
	return os.OpenFile(path, flag, perm)

     * 
     */
    public static final int FILE_SUPERSEDE = 0x0;
    /**
     * 
     */
    public static final int FILE_OPEN = 0x1;
    /**
     * 
     */
    public static final int FILE_CREATE = 0x2;
    /**
     * 
     */
    public static final int FILE_OPEN_IF = 0x3;
    /**
     * 
     */
    public static final int FILE_OVERWRITE = 0x4;
    /**
     * 
     */

        hasModifier(KtTokens.OPEN_KEYWORD) -> {
            if (this is KtCallableDeclaration && !hasBody()) {
                val parentDeclaration = this.getElementParentDeclaration()
                if (parentDeclaration is KtClass && parentDeclaration.isInterface()) {
                    Modality.ABSTRACT
                } else {
                    Modality.OPEN
                }
            }

{!../../../docs_src/events/tutorial002.py!}
```

此处，`shutdown` 事件处理器函数在 `log.txt` 中写入一行文本 `Application shutdown`。

!!! info "说明"

    `open()` 函数中，`mode="a"` 指的是**追加**。因此这行文本会添加在文件已有内容之后，不会覆盖之前的内容。

!!! tip "提示"

    注意，本例使用 Python `open()` 标准函数与文件交互。

    这个函数执行 I/O（输入/输出）操作，需要等待内容写进磁盘。

    但 `open()` 函数不支持使用 `async` 与 `await`。

    因此，声明事件处理函数要使用 `def`，不能使用 `asnyc def`。

!!! info "说明"

{
    "description": "TensorFlow is an end-to-end open source platform for machine learning. It has a comprehensive, flexible ecosystem of tools, libraries, and community resources that lets researchers push the state-of-the-art in ML and developers easily build and deploy ML-powered applications.",
    "license": "Apache-2.0",
    "title": "TensorFlow",
    "upload_type": "software",
    "creators": [
        {
            "name": "TensorFlow Developers"
        }

 *         SmbNamedPipe.PIPE_TYPE_CALL );
 * </pre></td><td>
 * Open the Named Pipe foo for reading and writing. The pipe will behave like the <code>CallNamedPipe</code> interface.
 * </td></tr>
 * <tr><td width="20%"><pre>
 * new SmbNamedPipe( "smb1://server/IPC$/foo",
 *         SmbNamedPipe.PIPE_TYPE_RDWR |
 *         SmbNamedPipe.PIPE_TYPE_TRANSACT );
 * </pre></td><td>

 * endpoint) or <i>closed</i> (includes the endpoint) on that side. With three possibilities on each
 * side, this yields nine basic types of ranges, enumerated below. (Notation: a square bracket
 * ({@code [ ]}) indicates that the range is closed on that side; a parenthesis ({@code ( )}) means

    path = tmp_path / "test.txt"
    path.write_bytes(b"<file content>")
    path2 = tmp_path / "test2.txt"
    path2.write_bytes(b"<file content2>")

    client = TestClient(app)
    with path.open("rb") as file, path2.open("rb") as file2:
        response = client.post(
            "/files/",
            files=(
                ("files", ("test.txt", file)),
                ("files", ("test2.txt", file2)),
            ),

이 예제에서 `shutdown` 이벤트 핸들러 함수는 `"Application shutdown"`이라는 텍스트가 적힌 `log.txt` 파일을 추가할 것입니다.

!!! info "정보"
    `open()` 함수에서 `mode="a"`는 "추가"를 의미합니다. 따라서 이미 존재하는 파일의 내용을 덮어쓰지 않고 새로운 줄을 추가합니다.

!!! tip "팁"
    이 예제에서는 파일과 상호작용 하기 위해 파이썬 표준 함수인 `open()`을 사용하고 있습니다.

    따라서 디스크에 데이터를 쓰기 위해 "대기"가 필요한 I/O (입력/출력) 작업을 수행합니다.

    그러나 `open()`은 `async`와 `await`을 사용하지 않기 때문에 이벤트 핸들러 함수는 `async def`가 아닌 표준 `def`로 선언하고 있습니다.

!!! info "정보"

 * following lifecycle:
 *
 *  1. [Send request headers][writeRequest].
 *  2. Open a sink to write the request body. Either [known][newKnownLengthSink] or
 *     [chunked][newChunkedSink].
 *  3. Write to and then close that sink.
 *  4. [Read response headers][readResponseHeaders].
 *  5. Open a source to read the response body. Either [fixed-length][newFixedLengthSource],