how to remove all the same elements in a list python code example

Example 1: remove all of same value python list

x = [1, 2, 3, 2, 2, 2, 3, 4]
list(filter(lambda a: a != 2, x))

duplicate = [2, 4, 10, 20, 5, 2, 20, 4] 
print(list(set(duplicate))