R-用查找表替换多个变量的值

Question

说我们有这个数据框：

lookup <- data.frame(
  "value" = c("1", "2","F","M",0,1),
  "label" = c("May2018", "Dec2019",'Female','Male',"No","Yes"),
  "var_name" = c("V1","V1","V2","V2","V3","V3")
)

此查询表：

df[,paste0('V1','_unc')] <- lookup$label[match(unlist(df[,'V1']), lookup[,'value'])]
df[,paste0('V2','_unc')] <- lookup$label[match(unlist(df[,'V2']), lookup[,'value'])]
df[,paste0('V3','_unc')] <- lookup$label[match(unlist(df[,'V3']), lookup[,'value'])]

> df
   ID V1 V2 V3  V1_unc V2_unc  V3_unc
1 001  1  F  0 May2018 Female      No
2 002  1  M  1 May2018   Male May2018
3 003  2  F  1 Dec2019 Female <NA>

我想基于查找表创建“未编码”变量

我尝试了此操作，但是由于某些原因，它不适用于V3，有任何线索吗？

for (var in c('V1','V2','V3')) {
  df[,paste0(var,'_unc')] <- lookup$label[match(unlist(df[,var]), lookup[,'value'])]
}

我也在循环中进行了尝试（与V3相同）：

var formCol = new FormCollection(new Dictionary<string, Microsoft.Extensions.Primitives.StringValues>
{
    { "Field1", "String Value 1" },
    { "Field2", "String Value 2" },
    { "Field3", "String Value 3" }
});
// Call create controller with test data
_controller.Create(formCol);