"msg": "value is not a valid integer",
            "type": "type_error.integer"
        }
    ]
}
```

これは、パスパラメータ `item_id` が `int` ではない値 `"foo"` だからです。

<a href="http://127.0.0.1:8000/items/4.2" class="external-link" target="_blank">http://127.0.0.1:8000/items/4.2</a> で見られるように、intのかわりに `float` が与えられた場合にも同様なエラーが表示されます。

/// check | 確認

したがって、Pythonの型宣言を使用することで、**FastAPI**はデータのバリデーションを行います。

public interface OneSizeTestContainerGenerator<T, E extends @Nullable Object>
    extends TestSubjectGenerator<T>, TestContainerGenerator<T, E> {
  TestContainerGenerator<T, E> getInnerGenerator();

  Collection<E> getSampleElements(int howMany);

  CollectionSize getCollectionSize();

     */
    public void testDecode() throws Exception {
        final byte[] decodedData = Base64Util.decode(ENCODED_DATA);
        assertEquals("1", BINARY_DATA.length, decodedData.length);
        for (int i = 0; i < decodedData.length; i++) {
            assertEquals("2", BINARY_DATA[i], decodedData[i]);
        }
    }

     * Verify the CRUD mode.
     * @param crudMode The CRUD mode.
     * @param expectedMode The expected mode.
     * @param dictId The dictionary ID.
     */
    protected void verifyCrudMode(final int crudMode, final int expectedMode, final String dictId) {
        if (crudMode != expectedMode) {
            throwValidationError(messages -> {

        return null;
    }

    @Override
    public SqlClause xgetSqlClause() {
        return null;
    }

    @Override
    public int xgetNestLevel() {
        return 0;
    }

    @Override
    public int xgetNextNestLevel() {
        return 0;
    }

    @Override
    public boolean isBaseQuery() {
        return false;
    }

    @Override

    protected List<String> jvmOptions = new ArrayList<>();

    /** Lasta environment configuration */
    protected String lastaEnv;

    /** Timeout in seconds for job execution (-1 means no timeout) */
    protected int timeout = -1; // sec

    /** Flag indicating whether the process has timed out */
    protected boolean processTimeout = false;

    /**
     * Default constructor for ExecJob.

   *
   * <p><b>Note:</b> This hash code is consistent with exact equality of the calculated statistics,
   * including the floating point values. See the note on {@link #equals} for details.
   */
  @Override
  public int hashCode() {
    return Objects.hash(xStats, yStats, sumOfProductsOfDeltas);
  }

  @Override
  public String toString() {
    if (count() > 0) {
      return MoreObjects.toStringHelper(this)

# Déclare une variable comme étant une str
# et profitez de l'aide de votre IDE dans cette fonction
def main(user_id: str):
    return user_id


# Un modèle Pydantic
class User(BaseModel):
    id: int
    name: str
    joined: date
```
Qui peuvent ensuite être utilisés comme cela:

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

second_user_data = {
    "id": 4,

  @JvmStatic
  fun headerEntries(vararg elements: String?): List<Header> = List(elements.size / 2) { Header(elements[it * 2]!!, elements[it * 2 + 1]!!) }

  @JvmStatic
  fun repeat(
    c: Char,
    count: Int,
  ): String {
    val array = CharArray(count)
    Arrays.fill(array, c)
    return String(array)
  }

  /**
   * Okio buffers are internally implemented as a linked list of arrays. Usually this implementation

  }

  public void testKeysElementSet() {
    assertEquals(multimap().keySet(), multimap().keys().elementSet());
  }

  @MapFeature.Require(SUPPORTS_REMOVE)
  public void testKeysRemove() {
    int original = multimap().keys().remove(k0(), 1);
    assertEquals(max(original - 1, 0), multimap().get(k0()).size());
  }

  @CollectionSize.Require(ONE)
  @CollectionFeature.Require(SUPPORTS_ITERATOR_REMOVE)