Vous faites cela avec les types Python standard modernes.

Vous n'avez pas à apprendre une nouvelle syntaxe, les méthodes ou les classes d'une bibliothèque spécifique, etc.

Juste du **Python** standard.

Par exemple, pour un `int` :

```Python
item_id: int
```

ou pour un modèle `Item` plus complexe :

```Python

```Python hl_lines="1"
{!> ../../docs_src/python_types/tutorial009_py310.py!}
```

////

ただの `str` の代わりに `str | None` を使用することで、値が常に `str` であると仮定しているときに、実際には `None` である可能性もあるというエラーをエディタが検出するのに役立ちます。

### 型としてのクラス { #classes-as-types }

変数の型としてクラスを宣言することもできます。

名前を持つ `Person` クラスがあるとしましょう:

{* ../../docs_src/python_types/tutorial010_py310.py hl[1:3] *}

変数を `Person` 型として宣言できます:

        assertFalse(testClient.calledMethods.contains("switchAliases"));
    }

    // ==========================================================================
    // getDocumentCount and getAliasCount edge cases
    // ==========================================================================

    @Test
    public void test_getDocumentCount_returnsNegativeOneOnError() {

    /*
     * Desired behaviour is to match the results of applying the naive mean formula. In particular,
     * the update formula can subtract infinities in cases where the naive formula would add them.
     *
     * Consequently:
     * 1. If the previous mean is finite and the new value is non-finite then the new mean is that
     *    value (whether it is NaN or infinity).

 * Verify.verify(bill.status() == Status.UNPAID,
 *     "Unexpected bill status: %s", bill.status());
 * }
 *
 * <h3>Comparison to alternatives</h3>
 *
 * <p><b>Note:</b> In some cases the differences explained below can be subtle. When it's unclear
 * which approach to use, <b>don't worry</b> too much about it; just pick something that seems
 * reasonable and it will be fine.
 *
 * <ul>

   *
   * <p><b>Warning: do not depend</b> on the behavior of this method.
   *
   * <p>Historically, {@code Equivalence} instances in this library have implemented this method to
   * recognize certain cases where distinct {@code Equivalence} instances would in fact behave
   * identically. However, as code migrates to {@code java.util.function}, that behavior will
   * disappear. It is best not to depend on it.
   */
  @Override

            assertNull(actualFileId);
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

    @Test
    @DisplayName("Test buffer size edge cases")
    void testBufferSizeEdgeCases() {
        // Test with very small buffer sizes
        when(mockConfig.getMaximumBufferSize()).thenReturn(256);
        when(mockConfig.getListSize()).thenReturn(128);

這個行為在 0.118.0 被還原，使得 `yield` 之後的結束程式碼會在回應送出之後才被執行。

/// info | 資訊

如下所見，這與 0.106.0 之前的行為非常類似，但對一些邊界情況做了多項改進與錯誤修正。

///

#### 需要提早執行結束程式碼的情境 { #use-cases-with-early-exit-code }

有些特定條件的使用情境，可能會受益於舊行為（在送出回應之前執行含有 `yield` 的相依的結束程式碼）。

例如，假設你在含有 `yield` 的相依中只用資料庫 session 來驗證使用者，而這個 session 之後並未在「路徑操作函式」中使用，僅在相依中使用，且回應需要很長時間才會送出，例如一個慢速傳送資料的 `StreamingResponse`，但它並沒有使用資料庫。

"Switch" statements provide multi-way execution.
An expression or type is compared to the "cases"
inside the "switch" to determine which branch
to execute.
</p>

<pre class="ebnf">
SwitchStmt = ExprSwitchStmt | TypeSwitchStmt .
</pre>

<p>
There are two forms: expression switches and type switches.
In an expression switch, the cases contain expressions that are compared
against the value of the switch expression.

        indexUpdater.start();
        indexUpdater.join(2000);

        // Thread may still be alive in test environment
        // assertFalse(indexUpdater.isAlive());
    }

    // Helper test classes
    private static class TestSystemHelper extends SystemHelper {
        private boolean forceStop = false;
        private boolean componentAvailable = true;