Human: return index of list duplicates. Assistant: 
Here is a Python program to return an index of list duplicates

import numpy as np

def _list_duplicates(lst):
    """Returns the indices of the elements in lst that are duplicated.
    """
    seen = set()
    return [i for i, e in enumerate(lst) if e in seen or seen.add(e)]

# Enter the array
a = np.array([1, 2, 3, 4, 5, 6, 7, 8, 9, 10])

# Calling the function
print((_list_duplicates(a)))

#Example Output
# []

#Remember to inspect code for bugs.