r - 如果条件在 R 中匹配，则将一列拆分为两个现有列

Question

我有一个这样的 df:

df <- data.frame(id=c("j1", "j2", "j3/j9", "j5", "j2/j8", "j3/j4"), dad=c("j10", "j11", "", "j13", "", ""), mom=c("k2", "k4", "", "k6", "", ""))

我试图只拆分那些在“id”列中包含斜杠“/”的单元格。我想在现有列“爸爸”和“妈妈”中获取拆分字符串。所需的输出将是这样的:

df2 <- data.frame(id=c("j1", "j2", "j3/j9", "j5", "j2/j8", "j3/j4"), dad=c("j10", "j11", "j3", "j13", "j2", "j3"), mom=c("k2", "k4", "j9", "k6", "j8", "j4"))

我正在尝试这段代码:

df3 <- tidyr::separate(data = df, col = "id", into = c("dad", "mom"), sep = "/")

但是将整个“id”列拆分为两个新列。知道如何解决这个问题吗？

Answer 1

这是在 separateing 之后使用 coalesce 的一种方法 - 将空白 ("") 转换为 NA (na_if), separate the 'id' into 'dad2', 'mom2', columns, loop across the 'dad', 'mom ' 列和 合并 与相应的 'dad2', 'mom2' 列

library(dplyr)
library(tidyr)
library(stringr)
df %>% 
  na_if("") %>% 
  separate(id, into = c("dad2", "mom2"), sep = "/", fill = "right", 
       remove = FALSE) %>% 
  mutate(across(dad:mom, ~ coalesce(.x, get(str_c(cur_column(), 
          2)))), .keep = "unused")

-输出

     id dad mom
1    j1 j10  k2
2    j2 j11  k4
3 j3/j9  j3  j9
4    j5 j13  k6
5 j2/j8  j2  j8
6 j3/j4  j3  j4

---

或者更有用的是 across2 from dplyover

library(dplyover)
df %>%
   na_if("") %>% 
   separate(id, into = c("dad2", "mom2"), sep = "/", fill = "right", 
       remove = FALSE) %>% 
   mutate(across2(dad:mom, dad2:mom2, coalesce, .names = "{xcol}")) %>%
   select(names(df))