Paste multiple columns together and numbering-CodePudding

Data

row1=c("A","B","C")
row2=c("D","E",NA)
df=data.frame(rbind(row1,row2))
df

     X1 X2 X3
row1  A  B  C
row2  D  E  NA

I want to 2row & 1col data frame, and the type of data is character

for example,

"1. A - 2. B - 3. C"
"1. D - 2. E"

Is there any other way other than using a loop?

I saw tidyr::unite, do.call, sprintf, ... But it's hard to apply in my case.

The dimensions of the actual data are larger. Actual data has more than 10 columns.

CodePudding user response：

We could do it this way:

library(tidyverse)

df %>% 
  mutate(across(starts_with("X"), ~ paste0(parse_number(cur_column()), ". ", .), .names = 'new_{col}')) %>% 
  unite(New_Col, starts_with('new'), na.rm = TRUE, sep = ' - ') %>% 
  mutate(New_Col = str_replace(New_Col, ' \\- \\d{1,2}\\. NA', '')) %>% 
  select(New_Col) %>% 
  as_tibble()

 New_Col           
  <chr>             
1 1. A - 2. B - 3. C
2 1. D - 2. E