用多个定界符拆分列，保留定界符

Question

如何使用 %、- 和 + 作为可能的分隔符将字符列拆分为 3 列，同时将分隔符保留在新列中？

示例数据：

data <- data.table(x=c("92.1%+100-200","90.4%-1000+200", "92.8%-200+100", "99.2%-500-200","90.1%+500-200"))

所需数据示例：

data.desired <- data.table(x1=c("92.1%", "90.4%", "92.8%","99.2%","90.1%")
                           , x2=c("+100","-1000","-200","-500","+500")
                           , x3=c("-200","+200","+100","-200","-200"))

很高兴为一个好的答案和一些帮助提供积分！

Answer 1

我们可以使用 tidyr 中的 separate 进行拆分，并使用积极的前瞻性来保留分隔符：

data %>% separate(x, c("x1", "x2", "x3"), sep = "(?=\+|-)")
#       x1    x2   x3
# 1: 92.1%  +100 -200
# 2: 90.4% -1000 +200
# 3: 92.8%  -200 +100
# 4: 99.2%  -500 -200
# 5: 90.1%  +500 -200

也就是说，请注意，简单地除以 \+|- 我们会得到

data %>% separate(x, c("x1", "x2", "x3"), sep = "\+|-")
#       x1   x2  x3
# 1: 92.1%  100 200
# 2: 90.4% 1000 200
# 3: 92.8%  200 100
# 4: 99.2%  500 200
# 5: 90.1%  500 200

使用 (?=\+|-) 在 "nothing" 处拆分，以防紧接着我们有 + 或 -（不匹配）。

Answer 2

在 data.table 中相当于 tstrsplit:

data[, c("x1","x2","x3") := tstrsplit(x, "(?<=.)(?=[+-])", perl=TRUE) ]
data
#                x    x1    x2   x3
#1:  92.1%+100-200 92.1%  +100 -200
#2: 90.4%-1000+200 90.4% -1000 +200
#3:  92.8%-200+100 92.8%  -200 +100
#4:  99.2%-500-200 99.2%  -500 -200
#5:  90.1%+500-200 90.1%  +500 -200

Answer 3

这是一个使用base R

的选项

cbind(data, read.csv(text = gsub("(?=[+-])", ",", data$x, perl = TRUE), 
    header = FALSE, stringsAsFactors = FALSE, col.names = c('x1', 'x2', 'x3')))
#                x    x1    x2   x3
#1:  92.1%+100-200 92.1%   100 -200
#2: 90.4%-1000+200 90.4% -1000  200
#3:  92.8%-200+100 92.8%  -200  100
#4:  99.2%-500-200 99.2%  -500 -200
#5:  90.1%+500-200 90.1%   500 -200

用多个定界符拆分列，保留定界符

Split column by multiple delimiters, keeping delimiters

regex

r

strsplit

data.table