r - 使用 R 中的正则表达式将所有匹配项提取到新列

Question

在我的数据中，我有一列类似于以下示例的打开文本字段数据:

d <- tribble(
  ~x,
  "i am 10 and she is 50",
  "he is 32 and i am 22",
  "he may be 70 and she may be 99",
)

我想使用 regex 将所有两位数字提取到一个名为 y 的新列中。我有以下代码，它可以很好地提取第一个匹配项:

d %>%
  mutate(y = str_extract(x, "([0-9]{2})"))

# A tibble: 3 x 2
  x                              y    
  <chr>                          <chr>
1 i am 10 and she is 50          10   
2 he is 32 and i am 22           32   
3 he may be 70 and she may be 99 70 

但是，有没有办法使用一些标准分隔符(例如逗号)将两个数字提取到同一列？

Answer 1

我们还可以使用 tidyr 中的 extract 和 unite:

library(dplyr)
library(tidyr)

d %>%
  extract(x, c('y', 'z'), regex = "(\\d+)[^\\d]+(\\d+)", remove = FALSE) 

输出:

# A tibble: 3 x 3
  x                              y     z    
  <chr>                          <chr> <chr>
1 i am 10 and she is 50          10    50   
2 he is 32 and i am 22           32    22   
3 he may be 70 and she may be 99 70    99 

返回单列:

d %>%
  extract(x, c('y', 'z'), regex = "(\\d+)[^\\d]+(\\d+)", remove = FALSE) %>%
  unite('y', y, z, sep = ', ')

输出:

# A tibble: 3 x 3
  x                              y     
  <chr>                          <chr> 
1 i am 10 and she is 50          10, 50
2 he is 32 and i am 22           32, 22
3 he may be 70 and she may be 99 70, 99