“上下文管理器”是你可以在 `with` 语句中使用的任意 Python 对象。

例如，[你可以用 `with` 来读取文件](https://docs.python.org/3/tutorial/inputoutput.html#reading-and-writing-files)：

```Python
with open("./somefile.txt") as f:
    contents = f.read()
    print(contents)
```

在底层，`open("./somefile.txt")` 会创建一个“上下文管理器”对象。

当 `with` 代码块结束时，它会确保文件被关闭，即使期间发生了异常。

当你用 `yield` 创建一个依赖时，**FastAPI** 会在内部为它创建一个上下文管理器，并与其他相关工具结合使用。

	default:
		return xml.UnmarshalError(fmt.Sprintf("expected element type <LifecycleConfiguration>/<BucketLifecycleConfiguration> but have <%s>",
			start.Name.Local))
	}
	for {
		// Read tokens from the XML document in a stream.
		t, err := d.Token()
		if err != nil {
			if err == io.EOF {
				break
			}
			return err
		}

		if se, ok := t.(xml.StartElement); ok {

</p>

<p>
The assembler is based on the input style of the Plan 9 assemblers, which is documented in detail
<a href="https://9p.io/sys/doc/asm.html">elsewhere</a>.
If you plan to write assembly language, you should read that document although much of it is Plan 9-specific.
The current document provides a summary of the syntax and the differences with
what is explained in that document, and

     * - Run the test.
     * - Pull the relevant lines of output from the test into a testcases file.
     * - Test the output:
     * --- cat testcases | while read L; do
     *       X=($L)
     *       A=$( cd /b/c && sudo mkdir -p ${X[0]} && cd ${X[0]} && pwd |
     *           sed -e 's#^//*#/#' )
     *       B=$( cd /b/c && cd ${X[1]} && pwd )

     * - Run the test.
     * - Pull the relevant lines of output from the test into a testcases file.
     * - Test the output:
     * --- cat testcases | while read L; do
     *       X=($L)
     *       A=$( cd /b/c && sudo mkdir -p ${X[0]} && cd ${X[0]} && pwd |
     *           sed -e 's#^//*#/#' )
     *       B=$( cd /b/c && cd ${X[1]} && pwd )

 * MSIE clients using NTLM SSP. This is similar to {@code Authentication:
 * BASIC} but weakly encrypted and without requiring the user to re-supply
 * authentication credentials.
 * <p>
 * Read <a href="../../../ntlmhttpauth.html">jCIFS NTLM HTTP Authentication and the Network Explorer Servlet</a> for
 * complete details.
 *
 * @deprecated NTLMv1 only
 */
/**

        }
    }

    /**
     * Validate buffer access bounds
     *
     * @param buffer the buffer
     * @param offset offset to access
     * @param length length to read
     * @throws SmbException if access would exceed bounds
     */
    public void validateBufferAccess(byte[] buffer, int offset, int length) throws SmbException {
        totalValidations.incrementAndGet();

///

### Файл `.env` { #the-env-file }

У вас може бути файл `.env` із вмістом:

```bash
ADMIN_EMAIL="******@****.***"
APP_NAME="ChimichangApp"
```

### Зчитування налаштувань із `.env` { #read-settings-from-env }

Потім оновіть ваш `config.py` так:

{* ../../docs_src/settings/app03_an_py310/config.py hl[9] *}

/// tip | Порада

  //    monitor.enterXXX()/monitor.leave() will make it really clear
  //    which lock is held at any point in the code.
  //
  // 3. I think "enterWhen(notEmpty)" reads better than "notEmpty.enter()".
  //
  // TODO(user): Implement ReentrantLock features:
  //    - toString() method
  //    - getOwner() method
  //    - getQueuedThreads() method

  echo   jvm.config path: %MAVEN_PROJECTBASEDIR%\.mvn\jvm.config 1>&2
  echo   Java command: %JAVACMD% 1>&2
  if exist "%JVM_CONFIG_TEMP%" (
    del "%JVM_CONFIG_TEMP%" 2>nul
  )
  exit /b 1
)

rem Read the output file
if exist "%JVM_CONFIG_TEMP%" (
  if defined MAVEN_DEBUG_SCRIPT (
    echo [DEBUG] Temp file contents:
    type "%JVM_CONFIG_TEMP%"
  )