合并 tibble 中的行

Question

我想在表格中列出我的包中的所有功能。

到目前为止，我从包帮助文档中提取了所有功能和标题

library(magrittr)
package_info <- library(help = magrittr)$info[[2]]
package_info_tbl <- package_info %>% 
  stringr::str_split(pattern = "\\s+", n = 2, simplify = T) %>%
  tibble::as_tibble(.name_repair = "minimal")
colnames(package_info_tbl) <- c("Function", "Title")

package_info_tbl
#> # A tibble: 13 x 2
#>    Function     Title                                          
#>    <chr>        <chr>                                          
#>  1 "%$%"        magrittr exposition pipe-operator              
#>  2 "%<>%"       magrittr compound assignment pipe-operator     
#>  3 "%>%"        magrittr forward-pipe operator                 
#>  4 "%T>%"       magrittr tee operator                          
#>  5 "[[.fseq"    Extract function(s) from a functional sequence.
#>  6 "debug_fseq" Debugging function for functional sequences.   
#>  7 "debug_pipe" Debugging function for magrittr pipelines.     
#>  8 "extract"    Aliases                                        
#>  9 "freduce"    Apply a list of functions sequentially         
#> 10 "functions"  Extract the function list from a functional    
#> 11 ""           sequence.                                      
#> 12 "magrittr"   magrittr - Ceci n'est pas un pipe              
#> 13 "print.fseq" Print method for functional sequence.

^{由reprex 包(v0.3.0)于 2020 年 3 月 29 日创建}

我发现有些行是分开的，如果标题很长，会导致 2 行或更多行。如何合并这些行？

Answer 1

我们可以用NA值替换空白，用于fill替换列中的NA前一个值Function，group_by Function并为每个Function.

library(dplyr)

package_info_tbl %>%
  na_if('') %>%
  tidyr::fill(Function)  %>%
  group_by(Function) %>%
  summarise(Title = paste(Title, collapse = " "))


# A tibble: 12 x 2
#   Function   Title                                                
#   <chr>      <chr>                                                
# 1 [[.fseq    Extract function(s) from a functional sequence.      
# 2 %<>%       magrittr compound assignment pipe-operator           
# 3 %>%        magrittr forward-pipe operator                       
# 4 %$%        magrittr exposition pipe-operator                    
# 5 %T>%       magrittr tee operator                                
# 6 debug_fseq Debugging function for functional sequences.         
# 7 debug_pipe Debugging function for magrittr pipelines.           
# 8 extract    Aliases                                              
# 9 freduce    Apply a list of functions sequentially               
#10 functions  Extract the function list from a functional sequence.
#11 magrittr   magrittr - Ceci n'est pas un pipe                    
#12 print.fseq Print method for functional sequence.