如何根據 r 中的不同列聚合數據幀的字符數據

Question

我是 R 的新手。 我有一個這樣的數據框：

Category      description

Analysis     This is one
Hybrid       This is two
Other        This is three
Analysis     This is four
Other        This is five
Hybrid       This is six

我想以這樣的列表形式獲取每個類別的描述：

Category description

Analysis  ("This is one", "This is four")
Hybrid    ("This is two", "This is six")
Other     ("This is five", "This is three")

Answer 1

這是否有效：

library(dplyr)
df %>% group_by(Category) %>% 
  mutate(description = str_c('"',description, '"')) %>% 
    summarise(description = str_c('(',toString(description),')'))

`summarise()` ungrouping output (override with `.groups` argument)
# A tibble: 3 x 2
  Category description                            
  <chr>    <chr>                                  
1 Analysis "(\"This is one\", \"This is four\")"  
2 Hybrid   "(\"This is two\", \"This is six\")"   
3 Other    "(\"This is three\", \"This is five\")"

cat(x$description)
("This is one", "This is four") ("This is two", "This is six") ("This is three", "This is five")

使用的數據：

dput(df)
structure(list(Category = c("Analysis", "Hybrid", "Other", "Analysis", 
"Other", "Hybrid"), description = c("This is one", "This is two", 
"This is three", "This is four", "This is five", "This is six"
)), class = c("spec_tbl_df", "tbl_df", "tbl", "data.frame"), row.names = c(NA, 
-6L), spec = structure(list(cols = list(Category = structure(list(), class = c("collector_character", 
"collector")), description = structure(list(), class = c("collector_character", 
"collector"))), default = structure(list(), class = c("collector_guess", 
"collector")), skip = 1L), class = "col_spec"))

Answer 2

如果您希望數據位於原始 data.frame/tibble 內的嵌套列表中，這將是一個選項：

library(dplyr)
library(tidyr)
library(data.trable)
# reading in your dummy data
df <- data.table::fread("Category      description
Analysis     'This is one'
Hybrid       'This is two'
Other        'This is three'
Analysis     'This is four'
Other        'This is five'
Hybrid       'This is six'")

res <- df %>% 
  # helper line to prepare de read in data
  tidyr::unite("description", description:V4, sep = " ") %>% 
  # build a grouping you need
  dplyr::group_by(Category) %>% 
  # nest the wanted column to a list
  tidyr::nest(description)

res
# A tibble: 3 x 2
# Groups:   Category [3]
  Category data            
  <chr>    <list>          
1 Analysis <tibble [2 x 1]>
2 Hybrid   <tibble [2 x 1]>
3 Other    <tibble [2 x 1]>

res[2][[1]] 
[[1]]
# A tibble: 2 x 1
   description   
   <chr>         
1 'This is one' 
2 'This is four'

[[2]]
# A tibble: 2 x 1
  description  
  <chr>        
1 'This is two'
2 'This is six'

[[3]]
# A tibble: 2 x 1
  description    
  <chr>          
1 'This is three'
2 'This is five'