Julia lang remove duplicates in a list of tuples considering the second element

Question

Is there an easy way to remove duplicates of a list of tuples where for the duplicates only the second element is considered? For example when I have the following list:

a = [("a",1),("b",3),("c",4),("d",8),("e",1)]

I want to end up with:

a = [("b",3),("c",4),("d",8),("e",1)]

I doesn't matter if I keep "a" or "e".

Answer 1

Yes, you can use the unique(f, itr) method to do this; it returns the elements of itr where f returns unique values.

julia> unique(x->x[2], a)
4-element Array{Tuple{String,Int64},1}:
 ("a", 1)
 ("b", 3)
 ("c", 4)
 ("d", 8)