如何合并R数据框指定列，生成‘列名:值’格式的合并列？

这里提供几种可行的解决方案，适配不同的代码风格：

方法1：使用dplyr的rowwise + c_across #

这是tidyverse生态下直观的逐行处理方式：

library(dplyr)

df <- data.frame(
  Name = c("Alice", "Bob", "Charlie"),
  Age = c(25, 30, 27),
  Country = c("USA", "Canada", "UK"),
  Occupation = c("Engineer", "Doctor", "Teacher")
)

selected_cols <- c("Age", "Country")

df <- df %>%
  rowwise() %>%
  mutate(merged = paste(paste(selected_cols, c_across(all_of(selected_cols)), sep = ":"), collapse = ", ")) %>%
  ungroup()

• rowwise() 确保每行独立计算
• c_across(all_of(selected_cols)) 提取当前行指定列的所有值
• 内层paste生成单个“列名:值”对，外层paste用逗号加空格拼接所有对

方法2：使用purrr的pmap_chr #

适合喜欢函数式编程风格的场景：

library(dplyr)
library(purrr)

df <- df %>%
  mutate(merged = pmap_chr(select(., all_of(selected_cols)), 
                           ~paste(paste(selected_cols, c(...), sep = ":"), collapse = ", ")))

• select(., all_of(selected_cols)) 筛选出目标列
• pmap_chr 逐行遍历筛选后的列，c(...)捕获当前行的所有值
• 同样通过两层paste完成格式拼接

方法3：基础R实现（无需额外包） #

如果不想加载tidyverse包，可以直接用apply：

df <- data.frame(
  Name = c("Alice", "Bob", "Charlie"),
  Age = c(25, 30, 27),
  Country = c("USA", "Canada", "UK"),
  Occupation = c("Engineer", "Doctor", "Teacher")
)

selected_cols <- c("Age", "Country")

df$merged <- apply(df[, selected_cols], 1, function(x) {
  paste(paste(selected_cols, x, sep = ":"), collapse = ", ")
})

• apply(df[, selected_cols], 1, ...) 按行处理目标列
• 匿名函数内完成“列名:值”对的生成与拼接

以上三种方法最终都会生成你期望的merged列，输出示例：

[1] "Age:25, Country:USA"   "Age:30, Country:Canada" "Age:27, Country:UK"

内容的提问来源于stack exchange，提问作者Mike