from itertools import combinations

lstA = ['Harry Potter','1984','50 Shades','Dracula']
lstB = ['50 Shades','Dracula','1984','Harry Potter']

setA = set(combinations(lstA, 2))
setB = set(combinations(lstB, 2))

result = setA - setB

print(result)

lstB[1] = 'The Godfather'

setA = set(combinations(lstA, 2))
setB = set(combinations(lstB, 2))
resultA = setA - setB
resultB = setB.difference(x[::-1] for x in setA)
result = resultA | resultB
print(result)