r - 使用从 R 上的另一列中提取的信息创建新列

Question

我有一个数据框，其中一列包含用“;”分隔的多个信息，如下所示:

DF = data.frame(a = c(1,1,1,2,2), b = c('aaa','aaa','aba','abc','ccc'), 
                extra_info = c(
                  'animal=horse;color=orange;shape=circle',
                  'animal=monkey;shape=square;value=532',
                  'animal=horse;color=blue;shape=square;value=321',
                  'animal=dog;color=green;value=678',
                  'color=pink;shape=triangle'
                ))

我无法使用read.table，因为我已经使用不同的函数来读取数据(而且extra_info列中每一行的内容都不同，并且列会困惑)。我想要做的是将所有这些信息分成不同的列，并相应地分配适当的名称，例如:

a   b   animal  color   shape    value
1  aaa  horse   orange  circle   NA
1  aaa  monkey  NA      square   532
1  aba  horse   blue    square   321
2  abc  dog     green   NA       678
2  ccc  NA      pink    triangle NA

到目前为止，我已经尝试过:

new_cols = DF %>% separate(extra_info, c(LETTERS[1:4]), sep = ";")

new_cols %>% separate(A, c("key","value"), sep = '=') %>% 
  separate(B, c("key","value"), sep = '=') %>%
  separate(C, c("key","value"), sep = '=') %>%
  separate(D, c("key","value"), sep = '=') %>%
  pivot_wider(names_from = c("key"), values_from = c("value"))

但它没有按预期工作。

Answer 1

这是一种方法，我将键值对的语法更改为有效的 JSON 语法，并使用 jsonlite::fromJSON 解析它:

library(purrr)
library(dplyr)
library(stringr)
library(jsonlite)
DF %>%
  mutate(
    json = str_replace_all(extra_info, pattern = "\\b", replacement = '"'),
    json = str_replace_all(json, pattern = fixed("="), replacement = ":"),
    json = str_replace_all(json, pattern = fixed(";"), replacement = ","),
    json = paste("{", json, "}"),
  ) %>%
  pull(json) %>%
  map(jsonlite::fromJSON) %>%
  map(as.data.frame) %>%
  bind_rows %>%
  cbind(DF, .)
#   a   b                                     extra_info animal  color    shape value
# 1 1 aaa         animal=horse;color=orange;shape=circle  horse orange   circle  <NA>
# 2 1 aaa           animal=monkey;shape=square;value=532 monkey   <NA>   square   532
# 3 1 aba animal=horse;color=blue;shape=square;value=321  horse   blue   square   321
# 4 2 abc               animal=dog;color=green;value=678    dog  green     <NA>   678
# 5 2 ccc                      color=pink;shape=triangle   <NA>   pink triangle  <NA>