用R分割宽格式的日期

Question

如果原始变量包含“后置”和“前”，如下面的示例所示，您有将日期从一列拆分为R中的两列的解决方案吗？

library(data.table)
library(splitstackshape)
date <- c("2012-2015","2016","after 2006", "before 1930")

df <- data.table(date)
df_l <- splitstackshape::cSplit(df, "date", sep = "-", direction = "wide")
df_l

# how can I achieve this

df_l$date_1 <- c( "2012", "2016", "2006", "1900")
df_l$date_2 <- c( "2015", "NA", "2022", "1930")
df_l

Answer 1

library(tidyverse)
data.frame(date) %>%
  mutate(date1 = str_replace_all(date, 
                    c('after (.*)' = '\\1-2022', before = '1900'))) %>%
  separate(date1, c('date_1', 'date_2'), convert = TRUE, fill = 'right')

        date date_1 date_2
1   2012-2015   2012   2015
2        2016   2016     NA
3  after 2006   2006   2022
4 before 1930   1900   1930