import math as mt
def generate_gray_list(my_val):
    if (my_val <= 0):
        return
    my_list = list()
    my_list.append("0")
    my_list.append("1")
    i = 2
    j = 0
    while(True):
        if i >= 1 << my_val:
            break
        for j in range(i - 1, -1, -1):
            my_list.append(my_list[j])
        for j in range(i):
            my_list[j] = "0" + my_list[j]
        for j in range(i, 2 * i):
            my_list[j] = "1" + my_list[j]
        i = i << 1
    for i in range(len(my_list)):
        print(my_list[i])
my_num = 3
print("The number is :")
print(my_num)
print("Method to convert gray code to binary is being called...")
generate_gray_list(my_num)

The number is :
3
Method to convert gray code to binary is being called...
000
001
011
010
110
111
101
100