例如，<a href="https://docs.python.org/zh-cn/3/tutorial/inputoutput.html#reading-and-writing-files" class="external-link" target="_blank">你可以使用`with`读取文件</a>：

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

在底层，`open("./somefile.txt")`创建了一个被称为"上下文管理器"的对象。

当 `with` 代码块结束时，它会确保关闭文件，即使发生了异常也是如此。

当你使用 `yield` 创建一个依赖项时，**FastAPI** 会在内部将其转换为上下文管理器，并与其他相关工具结合使用。

		return nil, BucketRemoteTargetNotFound{Bucket: bucket}
	}
	if reloaded {
		globalBucketTargetSys.set(bucket, meta)
	}
	return meta.bucketTargetConfig, nil
}

// GetConfigFromDisk read bucket metadata config from disk.
func (sys *BucketMetadataSys) GetConfigFromDisk(ctx context.Context, bucket string) (BucketMetadata, error) {
	objAPI := newObjectLayerFn()
	if objAPI == nil {

        try {
            final InputStream is = request.getInputStream();
            try {
                final byte[] buf = new byte[1024];
                while ((is.read(buf)) != -1) {}
            } catch (final Exception ignored) {} finally {
                try {
                    is.close();
                } catch (final Exception ignored) {}
            }

    accessed by another process" error. The <code>FILE_SHARE_READ</code>,
    <code>FILE_SHARE_WRITE</code>, and <code>FILE_SHARE_DELETE</code> may be
    combined with the bitwise OR '|' to specify that other peocesses may read,
    write, and/or delete the file while the jCIFS user has the file open.
     *
     * @param url An smb URL representing the file to write to

And when using `Depends(scope="request")` (the default), the exit code after `yield` is executed after the response is sent.

You can read more about it in the docs for [Dependencies with `yield` - Early exit and `scope`](../tutorial/dependencies/dependencies-with-yield.md#early-exit-and-scope).

 * Unlike many other double-ended priority queues, it stores elements in a single array, as compact
 * as the traditional heap data structure used in {@link PriorityQueue}.
 *
 * <p>This class is not thread-safe, and does not accept null elements.
 *
 * <p><i>Performance notes:</i>
 *
 * <ul>
 *   <li>If you only access one end of the queue, and do use a maximum size, this class will perform

  val ANY_VALUE =
    object : DerAdapter<AnyValue> {
      override fun matches(header: DerHeader): Boolean = true

      override fun fromDer(reader: DerReader): AnyValue {
        reader.read("ANY") { header ->
          val bytes = reader.readUnknown()
          return AnyValue(
            tagClass = header.tagClass,
            tag = header.tag,
            constructed = header.constructed,

        int maxCount = buf.dec_ndr_long();
        int offset = buf.dec_ndr_long();
        int actualCount = buf.dec_ndr_long();

        if (actualCount <= 0) {
            return "";
        }

        // Read wide string data (UTF-16LE)
        int byteCount = (actualCount - 1) * 2; // Exclude null terminator
        byte[] wideBytes = new byte[byteCount];
        buf.readOctetArray(wideBytes, 0, byteCount);

```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()
```

        // Override init to capture parameter calls
        networkExplorer = new NetworkExplorer() {
            @Override
            public void init(ServletConfig config) throws ServletException {
                // Read the parameters to trigger verification
                config.getInitParameter("jcifs.smb.client.domain");
                config.getInitParameter("jcifs.http.enableBasic");

                // Set required fields