```Python
from typing import Optional

from fastapi import FastAPI

app = FastAPI()


@app.get("/")
def read_root():
    return {"Hello": "World"}


@app.get("/items/{item_id}")
def read_item(item_id: int, q: Optional[str] = None):
    return {"item_id": item_id, "q": q}
```

* Vous devriez maintenant avoir une structure de répertoire telle que :

```
.
├── app
│   └── main.py
└── Dockerfile
```

  /** intValue returns current value. */
  public void testIntValue() {
    AtomicDouble at = new AtomicDouble();
    assertEquals(0, at.intValue());
    for (double x : VALUES) {
      at.set(x);
      assertEquals((int) x, at.intValue());
    }
  }

  /** longValue returns current value. */
  public void testLongValue() {
    AtomicDouble at = new AtomicDouble();
    assertEquals(0L, at.longValue());

			continue
		}
		if !strings.HasPrefix(obj.Name, rule.Prefix()) {
			continue
		}
		if rule.Filter.TestTags(obj.UserTags) {
			rules = append(rules, rule)
		}
	}
	sort.Slice(rules, func(i, j int) bool {
		return rules[i].Priority > rules[j].Priority && rules[i].Destination.String() == rules[j].Destination.String()
	})

	return rules
}

// GetDestination returns destination bucket and storage class.

		results = append(results, webhookAnalysis{
			Name:     mwc.Name,
			Revision: rev,
			Injected: injected,
			Reason:   reason,
		})
	}
	sort.Slice(results, func(i, j int) bool {
		return results[i].Name < results[j].Name
	})
	return results
}

func analyzeWebhooksMatchStatus(whs []admitv1.MutatingWebhook, podLabels, nsLabels map[string]string) (reason string, injected bool) {

  @CheckForNull
  private static <X> X newFromConstructor(Constructor<X> constructor, Throwable cause) {
    Class<?>[] paramTypes = constructor.getParameterTypes();
    Object[] params = new Object[paramTypes.length];
    for (int i = 0; i < paramTypes.length; i++) {
      Class<?> paramType = paramTypes[i];
      if (paramType.equals(String.class)) {
        params[i] = cause.toString();
      } else if (paramType.equals(Throwable.class)) {

        // this is not too great as it depends on timing/clockskew
        // first we need to obtain a ticket, therefor need valid credentials
        // then we need to wait until the ticket is expired
        int wait = 10 * 1000;
        long princExp = start + ( wait / 2 );
        Subject s = getInitiatorSubject(getTestUser(), getTestUserPassword(), getTestUserDomainRequired(), princExp);

```

////

Die Funktionsparameter werden wie folgt erkannt:

* Wenn der Parameter auch im **Pfad** deklariert wurde, wird er als Pfad-Parameter interpretiert.
* Wenn der Parameter ein **einfacher Typ** ist (wie `int`, `float`, `str`, `bool`, usw.), wird er als **Query**-Parameter interpretiert.
* Wenn der Parameter vom Typ eines **Pydantic-Modells** ist, wird er als Request**body** interpretiert.

/// note | "Hinweis"

```

////

//// tab | Python 3.8+

```Python hl_lines="18"
{!> ../../docs_src/body/tutorial004.py!}
```

////

函数参数按如下规则进行识别：

- **路径**中声明了相同参数的参数，是路径参数
- 类型是（`int`、`float`、`str`、`bool` 等）**单类型**的参数，是**查询**参数
- 类型是 **Pydantic 模型**的参数，是**请求体**

/// note | "笔记"

因为默认值是 `None`， FastAPI 会把 `q` 当作可选参数。

FastAPI 不使用 `Optional[str]` 中的 `Optional`， 但 `Optional` 可以让编辑器提供更好的支持，并检测错误。

```

Os parâmetros da função serão reconhecidos conforme abaixo:

* Se o parâmetro também é declarado na **rota**, será utilizado como um parâmetro de rota.
* Se o parâmetro é de um **tipo único** (como `int`, `float`, `str`, `bool`, etc) será interpretado como um parâmetro de **consulta**.
* Se o parâmetro é declarado como um **modelo Pydantic**, será interpretado como o **corpo** da requisição.

/// note | "Observação"

    assertEquals("20", Strings.repeat(input, 1));
    assertEquals("2020", Strings.repeat(input, 2));
    assertEquals("202020", Strings.repeat(input, 3));

    assertEquals("", Strings.repeat("", 4));

    for (int i = 0; i < 100; ++i) {
      assertEquals(2 * i, Strings.repeat(input, i).length());
    }

    assertThrows(IllegalArgumentException.class, () -> Strings.repeat("x", -1));
    assertThrows(