When I execute the following code:
my_list = [ ["u",1], ["u",2], ["a",1], ["d", 1], ["a",2],["d",2]]
collect(IterTools.groupby(s->s[1], my_list))
I get as output:
[["u", 1], ["u", 2]]
[["a", 1]]
[["d", 1]]
[["a", 2]]
[["d", 2]]
So it seems that the items with key a and d are not properly grouped together.
Environment:
Julia v1.10.9
itertools v1.10.0