I am using
rf['email'].errors
As said in docs, I can use it to have array of errors.
[str(e) for e in rf['email'].errors] #give me ["<django.utils.functional.__proxy__>"]
If repr or str - it gives ul's or string of array.
So it worked only when I used repr and eval together. But I think its stupid solution.
eval(`rf['email'].errors`)