}

  /** Returns a joiner which automatically places {@code separator} between consecutive elements. */
  public static Joiner on(char separator) {
    return new Joiner(String.valueOf(separator));
  }

  private final String separator;

  private Joiner(String separator) {
    this.separator = checkNotNull(separator);
  }

  private Joiner(Joiner prototype) {
    this.separator = prototype.separator;
  }

  }

  /** Returns a joiner which automatically places {@code separator} between consecutive elements. */
  public static Joiner on(char separator) {
    return new Joiner(String.valueOf(separator));
  }

  private final String separator;

  private Joiner(String separator) {
    this.separator = checkNotNull(separator);
  }

  private Joiner(Joiner prototype) {
    this.separator = prototype.separator;
  }

# Model Pydantic
class User(BaseModel):
    id: int
    name: str
    joined: date
```

A one będą mogły zostać później użyte w następujący sposób:

```Python
my_user: User = User(id=3, name="John Doe", joined="2018-07-19")

second_user_data = {
    "id": 4,
    "name": "Mary",
    "joined": "2018-11-30",
}

my_second_user: User = User(**second_user_data)
```

/// info

  }

  private static void checkNoOutput(Joiner joiner, Iterable<Integer> set) {
    assertEquals("", joiner.join(set));
    assertEquals("", joiner.join(set.iterator()));

    Object[] array = newArrayList(set).toArray(new Integer[0]);
    assertEquals("", joiner.join(array));

    StringBuilder sb1FromIterable = new StringBuilder();
    assertSame(sb1FromIterable, joiner.appendTo(sb1FromIterable, set));

   * {@code joiner}.
   *
   * <p><b>{@code Stream} equivalent:</b> {@code joiner.join(stream.iterator())}, or, if you are not
   * using any optional {@code Joiner} features, {@code
   * stream.collect(Collectors.joining(delimiter)}.
   *
   * @since 18.0
   */
  public final String join(Joiner joiner) {
    return joiner.join(this);
  }

  /**

   * {@code joiner}.
   *
   * <p><b>{@code Stream} equivalent:</b> {@code joiner.join(stream.iterator())}, or, if you are not
   * using any optional {@code Joiner} features, {@code
   * stream.collect(Collectors.joining(delimiter)}.
   *
   * @since 18.0
   */
  public final String join(Joiner joiner) {
    return joiner.join(this);
  }

  /**

{!> ../../docs_src/python_types/tutorial008b_py310.py!}
```

////

//// tab | Python 3.8+

```Python hl_lines="1  4"
{!> ../../docs_src/python_types/tutorial008b.py!}
```

////

In beiden Fällen bedeutet das, dass `item` ein `int` oder ein `str` sein kann.

#### Vielleicht `None`

Sie können deklarieren, dass ein Wert ein `str`, aber vielleicht auch `None` sein kann.

n-null-max.dyn.expect-noinput", "src/compress/flate/testdata/huffman-null-max.golden", "src/compress/flate/testdata/huffman-null-max.in", "src/compress/flate/testdata/huffman-null-max.wb.expect", "src/compress/flate/testdata/huffman-null-max.wb.expect-noinput", "src/compress/flate/testdata/huffman-pi.dyn.expect", "src/compress/flate/testdata/huffman-pi.dyn.expect-noinput", "src/compress/flate/testdata/huffman-pi.golden", "src/compress/flate/testdata/huffman-pi.in", "src/compress/flate/testdata/h...

kann auch als gültige **FastAPI**-Abhängigkeit verwendet werden.

Tatsächlich verwendet FastAPI diese beiden Dekoratoren intern.

///

## Eine Datenbank-Abhängigkeit mit `yield`.

Sie könnten damit beispielsweise eine Datenbanksession erstellen und diese nach Abschluss schließen.

n-null-max.dyn.expect-noinput", "src/compress/flate/testdata/huffman-null-max.golden", "src/compress/flate/testdata/huffman-null-max.in", "src/compress/flate/testdata/huffman-null-max.wb.expect", "src/compress/flate/testdata/huffman-null-max.wb.expect-noinput", "src/compress/flate/testdata/huffman-pi.dyn.expect", "src/compress/flate/testdata/huffman-pi.dyn.expect-noinput", "src/compress/flate/testdata/huffman-pi.golden", "src/compress/flate/testdata/huffman-pi.in", "src/compress/flate/testdata/h...