Question

我想使用scala对列值进行分组，例如

sunny,hot,high,FALSE,no
sunny,hot,high,TRUE,no
overcast,hot,high,FALSE,yes
rainy,mild,high,FALSE,yes
rainy,cool,normal,FALSE,yes
overcast,cool,normal,TRUE,yes

我希望结果为，

对于Ist列.........

Ist group

sunny,hot,high,FALSE,no
sunny,hot,high,TRUE,no

IInd组

overcast,hot,high,FALSE,yes
overcast,cool,normal,TRUE,yes

IIIrd group

rainy,mild,high,FALSE,yes
rainy,cool,normal,FALSE,yes

对于第二栏.........

Ist group

hot,high,FALSE,no
hot,high,TRUE,no
hot,high,FALSE,yes

IInd组

cool,normal,FALSE,yes
cool,normal,TRUE,yes

IIIrd group

mild,high,FALSE,yes

同样所有列到最后一列............

Answer 1

使用Seq.groupBy方法。

val data = Seq(("sunny", "hot", "high", "FALSE", "no"),
  ("sunny", "hot", "high", "TRUE", "no"),
  ("overcast", "hot", "high", "FALSE", "yes"),
  ("rainy", "mild", "high", "FALSE", "yes"),
  ("rainy", "cool", "normal", "FALSE", "yes"),
  ("overcast", "cool", "normal", "TRUE", "yes"))

val byFirst = data.groupBy(_._1)

结果：

Map(
    overcast -> List((overcast,hot,high,FALSE,yes), (overcast,cool,normal,TRUE,yes)), 
    rainy -> List((rainy,mild,high,FALSE,yes), (rainy,cool,normal,FALSE,yes)), 
    sunny -> List((sunny,hot,high,FALSE,no), (sunny,hot,high,TRUE,no)))

如何在scala中对类似的列值进行分组？

1 个答案: