AdvanceListSort.py

from collections import defaultdict

def advanced_sort(lst):
    """
    Create a function that takes a list of numbers or strings 
    and returns a list with the items from the original list 
    stored into sublists. Items of the same value should be in 
    the same sublist.
    Examples
    advanced_sort([2, 1, 2, 1]) ➞ [[2, 2], [1, 1]]

    advanced_sort([5, 4, 5, 5, 4, 3]) ➞ [[5, 5, 5], [4, 4], [3]]

    advanced_sort(["b", "a", "b", "a", "c"]) ➞ [["b", "b"], ["a", "a"], ["c"]]

    Notes
    The sublists should be returned in the order of each element's 
    first appearance in the given list.
    """
    d = defaultdict(list)
    for i in lst:
        d[i].append(i)
    return [l for l in d.values()]

if __name__ == "__main__":
    print(advanced_sort([2, 1, 2, 1]))
    print(advanced_sort([5, 4, 5, 5, 4, 3]))
    print(advanced_sort(["b", "a", "b", "a", "c"]))