atTotal += pool.Available
                if atTotal > choose && pool.Available > 0 {
                        return pool.Index
                }
        }
        // Should not happen, but print values just in case.
        panic(fmt.Errorf("reached end of serverPools (total: %v, atTotal: %v, choose: %v)", total, atTotal, choose))
}
```

## Other usages

### Advanced use cases with multiple ellipses

```Python
user_dict = user_in.dict()
```

dann haben wir jetzt in der Variable `user_dict` ein `dict` mit den gleichen Daten (es ist ein `dict` statt eines Pydantic-Modellobjekts).

Wenn wir es ausgeben:

```Python
print(user_dict)
```

bekommen wir ein Python-`dict`:

```Python
{
    'username': 'john',
    'password': 'secret',
    'email': '******@****.***',
    'full_name': None,
}
```

🚥 👆 💚 ⚙️ ⚠ ⤴️ ⏮️ 🎏 🔢 ⚠ 🐕‍🦺 ⚪️➡️ **FastAPI**, 👆 💪 🗄 & 🏤-⚙️ 🔢 ⚠ 🐕‍🦺 ⚪️➡️ `fastapi.exception_handlers`:

```Python hl_lines="2-5  15  21"
{!../../docs_src/handling_errors/tutorial006.py!}
```

// The logic to sort by last octet is implemented to
// prefer CIDRs with higher octets, this in-turn skips the
// localhost/loopback address to be not preferred as the
// first ip on the list. Subsequently this list helps us print
// a user friendly message with appropriate values.
func sortIPs(ipList []string) []string {
	if len(ipList) == 1 {
		return ipList
	}

	var ipV4s []net.IP
	var nonIPs []string

Sie könnten zum Beispiel eine Datei `main.py` haben mit:

```Python hl_lines="3"
import os

name = os.getenv("MY_NAME", "World")
print(f"Hello {name} from Python")
```

/// tip | "Tipp"

   *         return Math.sqrt((int) in);
   *       }
   *     };
   * Map<String, Double> transformed = Maps.transformValues(map, sqrt);
   * System.out.println(transformed);
   * }</pre>
   *
   * ... prints {@code {a=2.0, b=3.0}}.
   *
   * <p>Changes in the underlying map are reflected in this view. Conversely, this view supports
   * removal operations, and these are reflected in the underlying map.
   *

   *         return Math.sqrt((int) in);
   *       }
   *     };
   * Map<String, Double> transformed = Maps.transformValues(map, sqrt);
   * System.out.println(transformed);
   * }</pre>
   *
   * ... prints {@code {a=2.0, b=3.0}}.
   *
   * <p>Changes in the underlying map are reflected in this view. Conversely, this view supports
   * removal operations, and these are reflected in the underlying map.
   *

```Python hl_lines="2-5  15  21"
{!../../docs_src/handling_errors/tutorial006.py!}
```

is specified via the `role_policy` configuration parameter or the `MINIO_IDENTITY_OPENID_ROLE_POLICY` environment variable. The value is a comma-separated list of IAM access policy names already defined in the server. In this situation, the server prints a role ARN at startup that must be specified as a `RoleArn` API request parameter in the STS AssumeRoleWithWebIdentity API call. When using Role Policies, multiple OpenID providers and/or client applications (with unique client IDs) may be configured...

```Python
with open("./somefile.txt") as f:
    contents = f.read()
    print(contents)
```

在底层，`open("./somefile.txt")`创建了一个被称为"上下文管理器"的对象。

当 `with` 代码块结束时，它会确保关闭文件，即使发生了异常也是如此。

当你使用 `yield` 创建一个依赖项时，**FastAPI** 会在内部将其转换为上下文管理器，并与其他相关工具结合使用。

### 在使用 `yield` 的依赖项中使用上下文管理器