Python random shuffle [closed]

I am new to python would be great if anyone can give some tips on the following problem.

I have two sets with 12 elements each:

list1 = [1,2,3,4,5,6,7,8,9,10,11,12]
list2 = ["a", "b", "c","d","e","f","g","h","i","j","k","l"] 

My new list should have 3 elements from each list making it a total of 6 elements each. This is straight forward. I have four unique sets.

I would like to shuffle and repeat the experiment at least three times. However, the set of six elements should be unique.