Find all sequences with the same column value

Question

I have the following data frame:

╔══════╦═════════╗
║ Code ║ Airline ║
╠══════╬═════════╣
║    1 ║ AF      ║
║    1 ║ KL      ║
║    8 ║ AR      ║
║    8 ║ A         


        

Answer 1

You can try something like this in dplyr

library(dplyr)
df %>% group_by(code) %>% mutate(SharedWith = paste(sort(Airline), collapse = ', ')) %>% ungroup() %>% select(Airline, SharedWith)