```Python hl_lines="1  13"
{!../../docs_src/events/tutorial003.py!}
```

在 Python 中，  **上下文管理器**是一个你可以在 `with` 语句中使用的东西，例如，`open()` 可以作为上下文管理器使用。

```Python
with open("file.txt") as file:
    file.read()
```

Python 的最近几个版本也有了一个**异步上下文管理器**，你可以通过 `async with` 来使用：

```Python
async with lifespan(app):
    await do_stuff()
```

	errMetaCode := checkMetaHeaders(extractedSignedHeaders, r)
	if errMetaCode != ErrNone {
		return errMetaCode
	}

	// If the host which signed the request is slightly ahead in time (by less than globalMaxSkewTime) the
	// request should still be allowed.
	if pSignValues.Date.After(UTCNow().Add(globalMaxSkewTime)) {
		return ErrRequestNotReadyYet
	}

{* ../../docs_src/events/tutorial003.py hl[1,13] *}

파이썬에서 **컨텍스트 매니저**는 `with` 문에서 사용할 수 있는 것입니다. 예를 들어, `open()`은 컨텍스트 매니저로 사용할 수 있습니다:

```Python
with open("file.txt") as file:
    file.read()
```
최근 버전의 파이썬에서는 **비동기 컨텍스트 매니저**도 있습니다. 이를 `async with`와 함께 사용합니다:

```Python
async with lifespan(app):
    await do_stuff()
```

	// Distinguish these cases using the column number, since we don't
	// see the space itself. Note that text/scanner reports the position at the
	// end of the token. It's where you are now, and you just read this token.
	if tok == '(' && in.Stack.Col() == prevCol+1 {
		// Macro has arguments. Scan list of formals.
		acceptArg := true
		args = []string{} // Zero length but not nil.
	Loop:
		for {

                  }
                  /*
                   * Also look up an earlier node so that, if the graph is using MapRetrievalCache,
                   * we read one of the fields declared in that class.
                   */
                  Set<Integer> unused = graph.successors(first);
                  return null;
                }
              }));
    }

    get: Optional[Operation] = None
    put: Optional[Operation] = None
    post: Optional[Operation] = None
    delete: Optional[Operation] = None
    options: Optional[Operation] = None
    head: Optional[Operation] = None
    patch: Optional[Operation] = None
    trace: Optional[Operation] = None
    servers: Optional[list[Server]] = None
    parameters: Optional[list[Union[Parameter, Reference]]] = None

https://github.com/tensorflow/tensorflow/blob/master/tensorflow/tools/tf_sig_build_dockerfiles/devel.usertools/code_check_full.bats
Here are the affected tests:
EOF
    while read dep; do
      echo "For dependency $dep:"
      # For every missing dependency, find the tests which directly depend on
      # it, and print that list for debugging. Not really clear if this is

 * Note that each chaining method returns a new ordering instance which is backed by the previous
 * instance, but has the chance to act on values <i>before</i> handing off to that backing instance.
 * As a result, it usually helps to read chained ordering expressions <i>backwards</i>. For example,
 * when {@code compare} is called on the above ordering:
 *
 * <ol>
 *   <li>First, if only one {@code Foo} is null, that null value is treated as <i>greater</i>

		// we are attempting to read it.
		{
			volume: "exists",
			path:   "as-directory",
			err:    errFileNotFound,
		},
		// TestXLStorage case - 4.
		{
			volume: "exists",
			path:   "as-file-parent/as-file",
			err:    errFileNotFound,
		},
		// TestXLStorage case - 5.
		// Validate the good condition file exists and we are able to read it.
		{
			volume: "exists",

// PERFORMANCE, SUCH AS IN THE OPERATION OF NUCLEAR FACILITIES, AIRCRAFT
// NAVIGATION OR COMMUNICATION SYSTEMS, AIR TRAFFIC CONTROL, DIRECT LIFE
// SUPPORT MACHINES, OR WEAPONS SYSTEMS, IN WHICH THE FAILURE OF THE
// SOFTWARE COULD LEAD DIRECTLY TO DEATH, PERSONAL INJURY, OR SEVERE
// PHYSICAL OR ENVIRONMENTAL DAMAGE ("HIGH RISK ACTIVITIES").  WIDGET WORKSHOP
// SPECIFICALLY DISCLAIMS ANY EXPRESS OR IMPLIED WARRANTY OF FITNESS FOR
// HIGH RISK ACTIVITIES.
//