如何基于查找表替换列中的字符串值

Question

我有这个df。 我想根据查找表替换“ 1.1”，“ 2.1”，“ 3.2”等的每个实例。

查找表

所需的输出

我查看了基于查找表的数据框中的替换值，但不能解决我的问题。 提前致谢！

Answer 1

一个选项是gsubfn 。 我们将一个或多个数字与一个点（ [0-9.]+ ）进行匹配，并在替换中传递从第二个数据集（'df2'）创建的键/值对list 。 对于带有“键”的匹配模式，它将替换字符串中相应的“值”

library(gsubfn)
df1$Node <- gsubfn("([0-9.]+)", as.list(setNames(df2$Label,df2$Node)), df1$Node)
df1$Node
#[1] "One one > Two one > Three two" "One two > Two two > Three one" "One one > Two two > Three one" "One two > Two one > Three two"
#[5] "One one > Two two > Three two"

数据

df1 <- data.frame(ID = 1:5, Node = c("1.1 > 2.1 > 3.2", "1.2 > 2.2 > 3.1", "1.1 > 2.2 > 3.1", "1.2 > 2.1 > 3.2", "1.1 > 2.2 > 3.2"), stringsAsFactors = FALSE)

df2 <- data.frame(Label =  c("One one", "One two", "Two one", "Two two", "Three one", "Three two"), Node = c("1.1", "1.2", "2.1", "2.2", "3.1", "3.2"), stringsAsFactors = FALSE)