Und in den nächsten Abschnitten wird davon ausgegangen, dass Sie es bereits gelesen haben und dass Sie diese Haupt-Ideen kennen.

## Externe Kurse

	r := rand.New(rand.NewSource(time.Now().UnixNano()))
	permutes := r.Perm(len(buckets))
	// Add new buckets first
	for _, idx := range permutes {
		b := buckets[idx]
		if e := oldCache.find(b.Name); e == nil {
			bucketCh <- b
		}
	}
	for _, idx := range permutes {
		b := buckets[idx]
		if e := oldCache.find(b.Name); e != nil {
			cache.replace(b.Name, dataUsageRoot, *e)

Sie verfügt über eine *Pfadoperation*, die einen `Invoice`-Body empfängt, und einen Query-Parameter `callback_url`, der die URL für den Callback enthält.

Dieser Teil ist ziemlich normal, der größte Teil des Codes ist Ihnen wahrscheinlich bereits bekannt:

```Python hl_lines="9-13  36-53"
{!../../docs_src/openapi_callbacks/tutorial001.py!}
```

/// tip | "Tipp"

   * href="http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6409434">Sun bug 6409434</a> is fixed.
   * It's unclear whether nulls were to be permitted or forbidden, but presumably the eventual fix
   * will be to permit them, as it seems more likely that code would depend on that behavior than on
   * the other. Thus, we say the bug is in set(), which fails to support null.
   */
  @J2ktIncompatible
  @GwtIncompatible // reflection

      matrix:
        os: [ubuntu-latest, windows-latest]
        java: [17, 21]
      fail-fast: false

    runs-on: ${{ matrix.os }}

    steps:
      - uses: actions/checkout@v4
        with:
          persist-credentials: false

      - uses: actions/setup-java@v4
        with:
          java-version: ${{ matrix.java }}
          distribution: 'temurin'
          cache: 'maven'

      - name: Set up Maven

      # contents: read
      # actions: read

    steps:
      - name: "Checkout code"
        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
        with:
          persist-credentials: false

      - name: "Run analysis"
        uses: ossf/scorecard-action@62b2cac7ed8198b15735ed49ab1e5cf35480ba46 # v2.4.0
        with:
          results_file: results.sarif
          results_format: sarif

## Entwicklung

Wenn Sie das <a href="https://github.com/fastapi/fastapi" class="external-link" target="_blank">fastapi Repository</a> bereits geklont haben und tief in den Code eintauchen möchten, hier einen Leitfaden zum Einrichten Ihrer Umgebung.

### Virtuelle Umgebung mit `venv`

Você teria **um único objeto `engine`** para todo o seu código se conectar ao mesmo banco de dados.

{* ../../docs_src/sql_databases/tutorial001_an_py310.py ln[14:18] hl[14:15,17:18] *}

Usar `check_same_thread=False` permite que o FastAPI use o mesmo banco de dados SQLite em diferentes threads. Isso é necessário, pois **uma única requisição** pode usar **mais de uma thread** (por exemplo, em dependências).

  title="Server Name Indication (indication du nom du serveur)">SNI (indication du nom du serveur)</abbr></a>.
    * Cette extension SNI permet à un seul serveur (avec une seule adresse IP) d'avoir plusieurs certificats HTTPS et de servir plusieurs domaines/applications HTTPS.

 * typically false on Windows.
 *
 * If this returns false we won't permit simultaneous reads and writes. When writes commit we need
 * to delete the previous snapshots, and that won't succeed if the file is open. (We do permit
 * multiple simultaneous reads.)
 *
 * @param file a file in the directory to check. This file shouldn't already exist!
 */