如何在R中对8列数据框做列变换并转换为3列长表

Pandas（Python）实现 #

假设你已经筛选出包含business_id和7个星期营业时长列的宽数据框（列名如Monday、Tuesday...Sunday），用melt函数一步转成目标长表：

import pandas as pd

# df_wide 是你已处理好的宽表
df_long = df_wide.melt(
    id_vars='business_id',
    var_name='wday',
    value_name='duration'
)

如果你的星期列名是缩写格式（比如mon_duration），可以额外处理wday列统一格式：

# 示例：替换缩写为完整星期名
df_long['wday'] = df_long['wday'].map({
    'mon_duration': 'Monday',
    'tue_duration': 'Tuesday',
    'wed_duration': 'Wednesday',
    'thu_duration': 'Thursday',
    'fri_duration': 'Friday',
    'sat_duration': 'Saturday',
    'sun_duration': 'Sunday'
})

R 实现 #

用tidyr包的pivot_longer函数完成转换：

library(tidyr)

# df_wide 是你已处理好的宽表
df_long <- df_wide %>%
  pivot_longer(
    cols = -business_id,
    names_to = "wday",
    values_to = "duration"
  )

同样，若列名是缩写，可通过mutate调整：

df_long <- df_long %>%
  mutate(wday = recode(wday,
    "mon_duration" = "Monday",
    "tue_duration" = "Tuesday",
    "wed_duration" = "Wednesday",
    "thu_duration" = "Thursday",
    "fri_duration" = "Friday",
    "sat_duration" = "Saturday",
    "sun_duration" = "Sunday"
  ))

内容的提问来源于stack exchange，提问作者A.D