如何使用scala从列表中删除空列表？

Question

我有下面的列表结构 -

List(List(()), List(()), List(()), List(()), List(()), List(()), List(()), List(()), List(()), List(()), List(()), List(()), List(()), List(()), List(()), List(()), List(()), List(()), List(()), List({"esx":"192.168.20.52","vm":" naa.60a9800042704577762b45634476337a ","datastore":"","vNic":"","portGroupVLan":"","vSwitch":"","physicalNic":"","lunName":"lun_30102014_101347)","writeIops":44998,"readIops":1635,"latency":47008,"serialNumber":"BpEwv+EcDv3z","usedSize":0,"totalSize":4,"availableSize":4,"throughput":null},(),()), List(()), List(()), List(()), List(()), List(()), List(()), List(()), List(()), List(()), List(()), List(()), List(()), List(()), List(()), List(()), List(()), List(()), List(()), List(()), List((),(),()), List(()), List(()), List(()), List(()), List(()), List(()), List(()), List(()), List(()), List(()), List(()), List(()), List(()), List(()), List(()), List(()), List(()), List(()), List(()), List((),(),()), List(()), List(()), List(()), List(()), List(()), List(()), List(()), List(()), List(()), List(()), List(()), List(()), List(()), List(()), List(()), List(()), List(()), List(()), List(()), List((),(),())) 

我想从上面删除所有空列表。 我想作为输出 -

List({"esx":"192.168.20.52","vm":" naa.60a9800042704577762b45634476337a ","datastore":"","vNic":"","portGroupVLan":"","vSwitch":"","physicalNic":"","lunName":"lun_30102014_101347)","writeIops":44998,"readIops":1635,"latency":47008,"serialNumber":"BpEwv+EcDv3z","usedSize":0,"totalSize":4,"availableSize":4,"throughput":null}) 

如何获得上述输出使用Scala的？

Answer 1

如果输入是这样的，即你只有名单（名单（名单（）））的深度，两个人通话扁平化会解决这个问题。

val x = yourList 
x.flatten.flatten 

，如果你的列表中有不同深度空列表，你需要不断压扁，直到你到达一个固定点：

val x = yourList 
var y = x.flatten 
var z = y.flatten 
while (y != z) { 
    y = z 
    z = z.flatten 
y 

希望帮助:)