////

### 在 Python 中读取环境变量

您还可以在 Python 之外的地方（例如终端中或使用任何其他方法）创建环境变量，然后在 Python 中读取它们。

例如，您可以有一个名为 `main.py` 的文件，其中包含以下内容：

```Python hl_lines="3"
import os

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

/// tip

<a href="https://docs.python.org/3.8/library/os.html#os.getenv" class="external-link" target="_blank">`os.getenv()`</a> 的第二个参数是要返回的默认值。

        do {
          entryIndex = next - 1;
          entry = entries[entryIndex];
          next = CompactHashing.getNext(entry, mask);
        } while (next != srcNext);
        // here, entries[entryIndex] points to the old entry location; update it
        entries[entryIndex] = CompactHashing.maskCombine(entry, dstIndex + 1, mask);
      }
    } else {
      elements[dstIndex] = null;
      entries[dstIndex] = 0;
    }

  // `items` is a list of request-priorities.
  repeated PriorityLevelConfiguration items = 2;
}

// PriorityLevelConfigurationReference contains information that points to the "request-priority" being used.
message PriorityLevelConfigurationReference {
  // `name` is the name of the priority level configuration being referenced
  // Required.
  optional string name = 1;
}

                if (parent.getRelativePath() == null || parent.getRelativePath().isEmpty()) {
                    buffer.append(" and 'parent.relativePath' points at no local POM");
                } else {
                    buffer.append(" and 'parent.relativePath' points at wrong local POM");
                }
            }

            problems.add(new ModelProblemCollectorRequest(Severity.FATAL, ModelProblem.Version.BASE)

	const numDisks = 4
	path := t.TempDir()

	var fsDirs []string
	for i := 1; i <= numDisks; i++ {
		fsDirs = append(fsDirs, filepath.Join(path, fmt.Sprintf("disk%d", i)))
	}

	objLayer, _, err := initObjectLayer(ctx, mustGetPoolEndpoints(0, fsDirs...))
	if err != nil {
		removeRoots(fsDirs)
		t.Fatal(err)
	}

		if err != nil {
			finalMD5Bytes = append(finalMD5Bytes, []byte(part.ETag)...)
		} else {
			finalMD5Bytes = append(finalMD5Bytes, md5Bytes...)
		}
	}
	s3MD5 := fmt.Sprintf("%s-%d", getMD5Hash(finalMD5Bytes), len(parts))
	return s3MD5
}

// Clean unwanted fields from metadata
func cleanMetadata(metadata map[string]string) map[string]string {
	// Remove STANDARD StorageClass

resource in the list.
  * If you create HPA object using autoscaling/v1 API without specifying
targetCPUUtilizationPercentage and read it using kubectl it will print default
value as specified in extensions/v1beta1 (see details in [#23196](https://github.com/kubernetes/kubernetes/issues/23196)).
  * If a node or kubelet crashes with a volume attached, the volume will remain

  private final transient SortedMap<K, V> sortedDelegate;

  // The comparator used by this map.  It's the same as that of sortedDelegate,
  // except that when sortedDelegate's comparator is null, it points to a
  // non-null instance of Ordering.natural().
  // (cpovirk: Is sortedDelegate's comparator really ever null?)
  // The comparator will likely also differ because of our nullAccepting hack.

        @Override
        public String getAsString(final Object value) {
            if (value instanceof Date) {
                return DEFAULT_DATE_PRINTER.print(((Date) value).getTime());
            }
            return null;
        }

        @Override
        public Object getAsObject(final String value) {
            if (StringUtil.isEmpty(value)) {

* kubectl: fixes a regression with --use-openapi-print-columns that would not print object contents ([#65600](https://github.com/kubernetes/kubernetes/pull/65600), [@liggitt](https://github.com/liggitt))