list1 = [1, 2, 4]
list2 = [4, 5, 6]

set_difference = set(list1) - set(list2)
list_difference = list(set_difference)

print(list_difference)

#result
[1,2]

a = ['1', '2']
b = ['1', '2', '3', '4']
diff = list(set(a) - set(b))

['3', '4']

s = set(temp2)
temp3 = [x for x in temp1 if x not in s]