🔟 barrtodec -- turn a bitmap into a decimal integer using Python

barrtodec.py

"""
barrtodec.py -- turn a bitmap into a decimal integer using Python

This source code is licensed under a Creative Commons CC0 license.
More info at <https://creativecommons.org/publicdomain/zero/1.0/>.
"""

from functools import reduce


def barrtodec(bitarray):
    bits = "".join(str(bit) for bit in bitarray)
    return int(bits, 2)


def barrtodec2(bitarray):
    # This reduce-based approach should improve the performance,
    # since it doesn’t convert each and every bit into a string.
    return reduce(lambda array, bit: array << 1 | bit, bitarray)


if __name__ == "__main__":
    example = [1, 1, 1, 1, 1, 0]
    decimal = barrtodec(example)
    print(decimal)
    assert decimal == 62

    another_example = [1, 1, 0, 1, 1, 0, 0, 0, 1]
    another_decimal = barrtodec2(another_example)
    print(another_decimal)
    assert another_decimal == 433