def valid_subnet_masks():
    '''Generates a list of tuples containing the CIDR notation, dotted-decimal notation, and binary string representation of
    subnet masks /1 - /32

    :return: All possible ipv4 subnet masks in each of there major formats CIDR, dotted-decimal, and binary
    '''
    valid_masks = []

    # Create list of 32 binary strings of cidr notations from 1 - 32
    cidrs = [[x, '1' * x + '0' * (32 - x)] for x in range(1, 33)]

    for cidr, binary_string in enumerate(cidrs, start=1):
        binary_string = binary_string[1]
        # slice binary string into four 8 bit chunks
        octet_1 = binary_string[:8]
        octet_2 = binary_string[8:16]
        octet_3 = binary_string[16:24]
        octet_4 = binary_string[24:32]
        # convert each 8 bit string into an integer and add that to our list of subnets in its corresponding index
        valid_masks.append((cidr,
                            '{}.{}.{}.{}'.format(int(octet_1, 2), int(octet_2, 2), int(octet_3, 2), int(octet_4, 2)),
                            binary_string))
    return valid_masks


if __name__ == '__main__':

    for x in valid_subnet_masks():
        print(x)