如何基於查找表替換列中的字符串值

Question

我有這個df。 我想根據查找表替換“ 1.1”，“ 2.1”，“ 3.2”等的每個實例。

查找表

所需的輸出

我查看了基於查找表的數據框中的替換值，但不能解決我的問題。 提前致謝！

Answer 1

一個選項是gsubfn 。 我們將一個或多個數字與一個點（ [0-9.]+ ）進行匹配，並在替換中傳遞從第二個數據集（'df2'）創建的鍵/值對list 。 對於帶有“鍵”的匹配模式，它將替換字符串中相應的“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"

數據

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)