如何按条件合并dataframe的Ethnicity与Race列？

我有如下DataFrame：

> dput(df)
structure(list(Ethnicity = c("Non-Hispanic/Non-Latino", 
"Non-Hispanic/Non-Latino", "Non-Hispanic/Non-Latino", NA, "Non-Hispanic/Non-Latino", 
"Non-Hispanic/Non-Latino", "Hispanic/Latino", "Non-Hispanic/Non-Latino", 
"Non-Hispanic/Non-Latino", NA), Race = structure(c(1L, 
1L, 1L, NA, 5L, 1L, 7L, 1L, 7L, NA), levels = c("White", "2+ Races", 
"American Indian or Alaska Native", "Asian", "Black or African American", 
"Native Hawaiian or Other Pacific Islander", "Other", "Refused/Unknown"
), class = "factor")), row.names = c(NA, -10L), class = c("data.table", 
"data.frame"), .internal.selfref = <pointer: 0x7fe0098120e0>, index = integer(0))

需要合并Ethnicity和Race列的信息：

• 若个体的Ethnicity为Hispanic/Latino，则将该信息追加到Race列，格式为原Race值 (Hispanic/Latino)
• 若为Non-Hispanic/Non-Latino或NA，则Race列保持原内容不变

处理后的目标DataFrame如下：

> dput(r)
structure(list(Ethnicity = c("Non-Hispanic/Non-Latino", "Non-Hispanic/Non-Latino", 
"Non-Hispanic/Non-Latino", NA, "Non-Hispanic/Non-Latino", "Non-Hispanic/Non-Latino", 
"Hispanic/Latino", "Non-Hispanic/Non-Latino", "Non-Hispanic/Non-Latino", 
NA), Race = c("White ", "White", "White", NA, "Black or African American", 
"White", "Other (Hispanic/Latino)", "White", "Other", NA)), class = "data.frame", row.names = c(NA, 
-10L))

方法1：data.table 原生语法 #

原始数据为data.table类型，直接用条件赋值高效处理：

# 将Race从因子类型转为字符型
df[, Race := as.character(Race)]
# 对符合条件的行修改Race值
df[Ethnicity == "Hispanic/Latino", Race := paste(Race, "(Hispanic/Latino)")]

方法2：dplyr 语法 #

如果熟悉tidyverse风格，可用dplyr实现：

library(dplyr)

df_processed <- df %>%
  mutate(Race = as.character(Race)) %>%
  mutate(Race = if_else(Ethnicity == "Hispanic/Latino", 
                        paste(Race, "(Hispanic/Latino)"), 
                        Race))

执行上述任一代码后，即可得到目标格式的DataFrame。

内容的提问来源于stack exchange，提问作者Jamie