基于R语言DataFrame生成含Amenities与Name列的新数据集

现有如下R语言DataFrame：

df<-structure(list(state = c("West Bengal", "West Bengal", "West Bengal", 
"West Bengal", "West Bengal"), nn_hospital = c("Khundkuri Hospital", 
"Khundkuri Hospital", "Mankar Rural Hospital", "Khundkuri Hospital", 
"Khundkuri Hospital"), distance_nn_hospital = c(8949.68646563084, 
17217.1419457099, 16939.2318150416, 15812.9872649418, 1408.372117616
), nn_bank = c("contai", "contai", "Allahabad Bank", "contai", 
"contai"), distance_nn_bank = c(13959.9950089655, 20598.4763042432, 
19688.6296071566, 20537.3799009137, 11385.8738290783)), class = "data.frame", row.names = c(NA, 
5L))

需要生成仅包含Amenities和Name两列的新DataFrame：

• Amenities列取值为"nn_bank"或"nn_hospital"
• Name列对应原DataFrame中nn_bank或nn_hospital列的具体名称

方法一：使用tidyr包（推荐） #

借助tidyr的pivot_longer函数快速实现宽表转长表，筛选出目标列：

# 若未安装tidyr包，先执行安装
# install.packages("tidyr")
library(tidyr)

# 转换并提取目标列
new_df <- df %>%
  pivot_longer(
    cols = c(nn_hospital, nn_bank),  # 指定要转换的列
    names_to = "Amenities",          # 原列名存入Amenities列
    values_to = "Name"               # 原列值存入Name列
  ) %>%
  select(Amenities, Name)            # 只保留目标两列

# 查看结果
print(new_df)

方法二：Base R实现（无需额外包） #

通过手动构建子数据框再合并的方式实现：

# 构建医院相关数据框
hospital_df <- data.frame(
  Amenities = rep("nn_hospital", nrow(df)),
  Name = df$nn_hospital
)

# 构建银行相关数据框
bank_df <- data.frame(
  Amenities = rep("nn_bank", nrow(df)),
  Name = df$nn_bank
)

# 合并两个数据框
new_df <- rbind(hospital_df, bank_df)

# 查看结果
print(new_df)

两种方法最终得到的new_df结构完全符合需求，示例输出如下：

Amenities               Name
1 nn_hospital Khundkuri Hospital
2 nn_hospital Khundkuri Hospital
3 nn_hospital Mankar Rural Hospital
4 nn_hospital Khundkuri Hospital
5 nn_hospital Khundkuri Hospital
6    nn_bank              contai
7    nn_bank              contai
8    nn_bank      Allahabad Bank
9    nn_bank              contai
10   nn_bank              contai

内容的提问来源于stack exchange，提问作者firmo23