Automatically convert integers to hex strings

integer_conversion.py

def bytes_size(value):
    if value == 0:
        return 1
    size = (value.bit_length() + 7) // 8
    if value < 0 and not value & (1 << (size * 8 - 1)):
        size += 1
    return size


def integer_to_hex(value, decimals=0):
    if decimals % 2 != 0:
        decimals += 1
    nibbles = bytes_size(value) * 2
    hex_string = hex(value & (2 ** (nibbles * 4) - 1))[2:].upper()
    return ((nibbles if nibbles > decimals else decimals) - len(hex_string)) * ("F" if value < 0 else "0") + hex_string


def integer_to_str(value, decimals=0):
    if value < 0:
        decimals += 1
    return str(value).zfill(decimals)


if __name__ == '__main__':
    for i in range(256):
        print(-i)
        print(integer_to_hex(-i, 4))
        print(integer_to_str(-i, 3))
        print("----")