Find duplicates within and outside nested list in python

Question

I have a list s:

s=[[1,2,1],[2,2,1],[1,2,1]]

Case 1: Remove the duplicate groups in the list

Case 2: Remove the duplicate values within the groups

Desired Result:

Case 1 : [[1,2,1],[2,2,1]]
Case 2 : [[1,2],[2,1],[1,2]]

I tried using the list(set(s)) but it throws up an error:

unhashable type: 'list'

Answer 1

You need to know that it's not possible in Python to have a set of lists. The reason is that lists are not hashable. The simplest way to do your task in the first case is to use a new list of lists without duplicates such as below:

temp_list = []
for each_element in [[1,2,1],[2,2,1],[1,2,1]]:
    if each_element not in temp_list:
        temp_set.append(each_element)
print(temp_list)        

The output:

[[1, 2, 1], [2, 2, 1]]

The case2 is more simple:

temp_list = []
for each_element in [[1,2,1],[2,2,1],[1,2,1]]:
    temp_list.append(list(set(each_element)))
print(temp_list)        

And this is the output:

[[1, 2], [1, 2], [1, 2]]

However these codes are not the pythonic way of doing things, they are very simple to be understood by beginners.