Combining two lists and removing duplicates, without removing duplicates in original list

Question

I have two lists that i need to combine where the second list has any duplicates of the first list ignored. .. A bit hard to explain, so let me show an example of what the c

Answer 1

You can bring this down to one single line of code if you use numpy:

a = [1,2,3,4,5,6,7]
b = [2,4,7,8,9,10,11,12]

sorted(np.unique(a+b))

>>> [1,2,3,4,5,6,7,8,9,10,11,12]