How to count the frequency of the elements in an unordered list?

Question

I need to find the frequency of elements in an unordered list

a = [1,1,1,1,2,2,2,2,3,3,4,5,5]

output->

b =         


        

Answer 1

seta = set(a)
b = [a.count(el) for el in seta]
a = list(seta) #Only if you really want it.