def binary_digits_to_places(binary_string):
    """Given a string representing a binary value, return a list of the
    decimal values of the places for which the bit is on.
    0011 -> [1, 2]"""
    reversed_bits = reversed(binary_string)
    place_values = [
        2**exp for exp, digit in enumerate(reversed_bits) if digit == "1"]
    return place_values