pack consecutive duplicates of list elements into sublists python

1import itertools
2
3def pack_consecutive_duplicates(_list: list):
4    preprocessed_list = []
5    # x groups the duplicates into a tuple ()
6    # x[0] is the duplicate element
7    # x[1] is a grouper iterable that conatins all the duplicate elements
8    for x in itertools.groupby(_list):
9        amount = [*x[1]].count(x[0])
10        if amount > 1:
11            for k in range(0, amount):
12                preprocessed_list.append(x[0])
13        else:
14            preprocessed_list.append((x[0]))
15
16    return preprocessed_list