ones.py

def ones(num: int, number_of_bytes: int = 4) -> int:
    num_ones = 0
    for i in range(number_of_bytes * 8):
        if (2 ** i) & num:
            num_ones += 1
    return num_ones


def ones(num: int) -> int:
    bin_string = f"{num:b}"
    return list(bin_string).count("1")


def test_ones():
    assert ones(3) == 2
    assert ones(1 + 4 + 64) == 3
    assert ones(128) == 1
    assert ones(127) == 7