Python ProgrammingPython Programming

How do I find the duplicates in a list and create another list with them?

List of duplicates using collections

import collections


thelist = [1, 2, 3, 4, 4, 5, 5, 6, 1]
print([item for item, count in collections.Counter(thelist).items() if count > 1])
[1, 4, 5]

List of duplicates using iteration_utilities

from iteration_utilities import duplicates

thelist = [1, 2, 3, 4, 4, 5, 5, 6, 1]
print(list(duplicates(thelist)))

thelist = ['A', 'B', 'C', 'D', 'A']
print(list(duplicates(thelist)))
[4, 5, 1]
['A']