例えば、<a href="https://docs.python.org/3/tutorial/inputoutput.html#reading-and-writing-files" class="external-link" target="_blank">ファイルを読み込むには`with`を使用することができます</a>:

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

その後の`open("./somefile.txt")`は「コンテキストマネージャ」と呼ばれるオブジェクトを作成します。

`with`ブロックが終了すると、例外があったとしてもファイルを確かに閉じます。

`yield`を依存関係を作成すると、**FastAPI** は内部的にそれをコンテキストマネージャに変換し、他の関連ツールと組み合わせます。

/**
 * An immutable array of {@code int} values, with an API resembling {@link List}.
 *
 * <p>Advantages compared to {@code int[]}:
 *
 * <ul>
 *   <li>All the many well-known advantages of immutability (read <i>Effective Java</i>, third
 *       edition, Item 17).
 *   <li>Has the value-based (not identity-based) {@link #equals}, {@link #hashCode}, and {@link
 *       #toString} behavior you expect.

}

// Tests Pilot /debug
func TestDescribe(t *testing.T) {
	productPageConfigPath := "testdata/describe/http_config.json"
	config, err := os.ReadFile(productPageConfigPath)
	if err != nil {
		t.Fatalf("failed to read %s: %v", productPageConfigPath, err)
	}
	cases := []execAndK8sConfigTestCase{
		{ // case 0
			args:           []string{},
			expectedString: "Describe resource and related Istio configuration",
		},

    for (AtomicLong value : map.values()) {
      sum = sum + value.get();
    }
    return sum;
  }

  @LazyInit @CheckForNull private transient Map<K, Long> asMap;

  /** Returns a live, read-only view of the map backing this {@code AtomicLongMap}. */
  public Map<K, Long> asMap() {
    Map<K, Long> result = asMap;
    return (result == null) ? asMap = createAsMap() : result;
  }

   *   <li><b>If the character at the specified index is not a surrogate, it is returned.</b>
   *   <li>If the first character was a high surrogate value, then an attempt is made to read the
   *       next character.
   *       <ol>
   *         <li><b>If the end of the sequence was reached, the negated value of the trailing high
   *             surrogate is returned.</b>

        String encoding = null;
        try {
            bis = new BufferedInputStream(inputStream);
            final byte[] buffer = new byte[preloadSizeForCharset];
            final int size = bis.read(buffer);
            if (size != -1) {
                final String content = new String(buffer, 0, size);
                encoding = parseCharset(content);
            }
        } catch (final IOException e) {

    return Synchronized.biMap(bimap, null);
  }

  /**
   * Returns an unmodifiable view of the specified bimap. This method allows modules to provide
   * users with "read-only" access to internal bimaps. Query operations on the returned bimap "read
   * through" to the specified bimap, and attempts to modify the returned map, whether direct or via
   * its collection views, result in an {@code UnsupportedOperationException}.
   *

    return Synchronized.biMap(bimap, null);
  }

  /**
   * Returns an unmodifiable view of the specified bimap. This method allows modules to provide
   * users with "read-only" access to internal bimaps. Query operations on the returned bimap "read
   * through" to the specified bimap, and attempts to modify the returned map, whether direct or via
   * its collection views, result in an {@code UnsupportedOperationException}.
   *

    - [Node binaries](#node-binaries-12)
  - [Changelog since v1.18.5](#changelog-since-v1185)
  - [Urgent Upgrade Notes](#urgent-upgrade-notes)
    - [(No, really, you MUST read this before you upgrade)](#no-really-you-must-read-this-before-you-upgrade)
  - [Changes by Kind](#changes-by-kind-13)
    - [API Change](#api-change-2)
    - [Bug or Regression](#bug-or-regression-12)
  - [Dependencies](#dependencies-14)

# Concurrency and async / await

Details about the `async def` syntax for *path operation functions* and some background about asynchronous code, concurrency, and parallelism.

## In a hurry?

<abbr title="too long; didn't read"><strong>TL;DR:</strong></abbr>

If you are using third party libraries that tell you to call them with `await`, like:

```Python
results = await some_library()
```