palindrome/transform/Transform.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-
class Transform(object):
    """Class to transform a given integer into a palindrome"""
    # to avoid magic numbers.
    MAXIMUM_INPUT_VALUE = 1000000000
    INVALID_RETURN_VALUE = -1

    def __init__(self):
        super(Transform, self).__init__()

    def palindrome(self, integer):
        '''
        The main function. Checks if input integer is already a palindrome
        and trys calculating one if input integer is not already a palindrome.
        '''
        self.input_integer = integer
        if self.__is_palindrome(self.input_integer):
            print('Integer {} is a palindrome'.format(self.input_integer))
            return self.input_integer
        else:
            print('Integer {} is not a palindrome'.format(self.input_integer))
            print('Calculating the palindrome for input {}'.format(self.input_integer))  # noqa
            palindrome = self.__calculate_palindrome()
            return palindrome

    # The following methods are private. Signaled by the leading __
    def __is_palindrome(self, int_to_check):
        reversed_integer = self.__reverese_int(int_to_check)
        if self.input_integer == reversed_integer:
            return True
        else:
            return False

    def __reverese_int(self, int_to_reverse):
        reversed_integer = 0
        int_to_check = int_to_reverse
        while int_to_check > 0:
            reminder = int_to_check % 10
            reversed_integer = (reversed_integer * 10) + reminder
            int_to_check = int_to_check // 10
        return reversed_integer

    def __calculate_palindrome(self):
        reversed_integer = self.__reverese_int(self.input_integer)
        self.input_integer = self.input_integer + reversed_integer
        print('Possible palindrome is {}'.format(self.input_integer))
        if self.__is_palindrome(self.input_integer) is True:
            print('Possible palindrome is correct!')
            return self.input_integer
        elif not self.__is_palindrome(self.input_integer):
            print('Possible palindrome is wrong! Calcualte again!')
            while not self.__is_palindrome(self.input_integer):
                if self.input_integer >= self.MAXIMUM_INPUT_VALUE:
                    return self.INVALID_RETURN_VALUE
                else:
                    self.__calculate_palindrome()
            return self.input_integer