Spreading a two column data frame with tidyr

Question

I have a data frame that looks like this:

  a b
1 x 8
2 x 6
3 y 3
4 y 4
5 z 5
6 z 6

and I want to turn it into this:

  x y          


        

Answer 1

Another base answer (that also looks like fast):

data.frame(split(df$b,df$a))