how to get difference between two elements of list in python code example

Example 1: 2 list difference python

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]

Example 2: python list of difference beetwen values in list

v = np.diff(t)