the data set looks like
id agent final_col
1 1 A:A A
2 1 A:A A
3 2 B B
4 3 C C
5 4 A:C:C A:C
6 4 A:C:C A:C
7 4 A:C:C A:C
How can I remove duplicate entries, to have a clean column like the final_col
in R?