def duplicates(lst, item):   

    """ returns a list with indexes where element 'item' is repeated in list 'lst'
    Args:
        lst: `list` list to look for repeated elements  
        item: `undefined` elements to look indexes where is repeated in list 'lst'
    Returns: list with indexes where the element is repeated in input list
    """

    return [i for i, x in enumerate(lst) if x == item]