A simple Anti-Gray Code (And Gray Code too) generator in python 3.6+

anti_gray.py

#!/usr/bin/env python3

from functools import lru_cache

@lru_cache(maxsize=None)
def compute_gray_code(bits:int) -> list:
    if bits is 1:
        return [0, 1]
    else:
        smaller = compute_gray_code(bits - 1)
        return smaller + [v | 2 ** (bits-1) for v in smaller][::-1]

@lru_cache(maxsize=None)
def compute_anti_gray_code(bits:int) -> list:
    if (bits is 1):
        return [0, 1]

    max_int = (2 ** bits) - 1
    res = compute_gray_code(bits - 1)

    res = [value << 1 for value in res] # left shift


    res = sum([[value, (~value) & max_int] for value in res], []) # duplicate and complements
    return res

def anti_gray_code(value:int, bits:int) -> int:
    return compute_anti_gray_code(bits)[value]

def gray_code(value:int, bits:int) -> int:
    return compute_gray_code(bits)[value]

if __name__ == '__main__':
    from sys import argv
    from math import ceil
    def main():
        if len(argv) >= 3:
            value = int(argv[1])
            bits = int(argv[2])

            if value >= 2 ** bits - 1 or value < 0:
                print('Bad value or not enough bits')
                return
            res = anti_gray_code(value, bits)
            print(res)
            print(hex(res)[2:].zfill(ceil(bits / 4)).upper())
            print(bin(res)[2:].zfill(bits))
        else:
            print('USAGE :', argv[0], 'VALUE BITS')
    main()