如何将一个字段分成 3 个新列

Question

下面是数据。期望的结果如下。我将如何着手完成这样的任务？

  firm <- c("firm1","firm2","firm3","firm4")
  comment2 <- c(51,5104,"",510466)

  list <- data.frame(firm,comment2)

  name       comment2    commenta     commentb     commentc
  firm1      51           51
  firm2      5104         51            04
  firm3      
  firm4      510466       51            04            66

Answer 1

可以使用位置索引作为 sep in separate

library(dplyr)
library(tidyr)
library(stringr)
tibble(firm, comment2) %>%
     separate(comment2, into = str_c('comment', letters[1:3]), 
          sep= c(2, 4), remove = FALSE)

-输出

# A tibble: 4 x 5
#  firm  comment2 commenta commentb commentc
#  <chr> <chr>    <chr>    <chr>    <chr>   
#1 firm1 "51"     "51"     ""       ""      
#2 firm2 "5104"   "51"     "04"     ""      
#3 firm3 ""       ""       ""       ""      
#4 firm4 "510466" "51"     "04"     "66"

或者可以在 base R 中使用 strsplit 在正则表达式环视中执行此操作以拆分

df1 <- data.frame(firm, comment2)
df1[paste0('comment', letters[1:3])] <-  do.call(rbind, 
        lapply(lst1, `length<-`, max(lengths(lst1))))

如何将一个字段分成 3 个新列

How to break one field into 3 new columns

substring

r