以下是一个示例数据框：
x <- list(a = c("1", "2", "2, 3"), b = c("2", "3", "5, 6"), id = c("a1", "a2", "a3"))
x1 <- as.data.frame(x)
str(x1)
'data.frame': 3 obs. of 3 variables:
$ a : Factor w/ 3 levels "1","2","2, 3": 1 2 3
$ b : Factor w/ 3 levels "2","3","5, 6": 1 2 3
$ id: Factor w/ 3 levels "a1","a2","a3": 1 2 3
x1
a b id
1 2 a1
2 3 a2
2, 3 5, 6 a3
你看到x1 $ a和x1 $ b在位置上有两个值：＆＃34; 2,3＆＃34;和＆＃34; 5,6和＃34;，但在x1 $ id上只有一个值。
我的问题是，如果您知道分割这两个值的方法，请使用相同的$ id值创建一个第四个值。所以它看起来像这样：
str(x1)
'data.frame': 4 obs. of 3 variables:
$ a : Factor w/ 4 levels "1","2","2","3": 1 2 3 4
$ b : Factor w/ 4 levels "2","3","5","6": 1 2 3 4
$ id: Factor w/ 3 levels "a1","a2","a3", "a3": 1 2 3
x1
a b id
1 2 a1
2 3 a2
2 5 a3
3 6 a3
编辑：$ a和$ b始终具有相同数量的变量
Edit2：感谢Ronak Shah的工作
-> cSplit(x, c("a", "b"), ",", "long")