Python script to compare big digits.

compare_big_digits.py

#! /usr/local/bin/python3.6
"""
Comparison between two big-digit integers
"""
import random
import sys
import traceback


class CompareBigDigits:
    D_L = 1000  # Number of big-digit integer (Left-hand side)
    D_R = 1001  # Number of big-digit integer (Right-hand side)

    def __init__(self):
        self.l = [random.randrange(10) for _ in range(self.D_L)]
        self.r = [random.randrange(10) for _ in range(self.D_R)]

    def exec(self):
        """ Execution """
        try:
            s = self.__compare(self.l, self.r)
            self.__display(self.l, self.r, s)
        except Exception as e:
            raise

    def __compare(self, l, r):
        """ Comparison

        :param list l
        :param list r
        :return int s: 1 (l > r)
                       0 (l = r)
                      -1 (l < r)
        """
        try:
            size_l, size_r = len(l), len(r)
            if size_l > size_r:
                for i in range(size_l - 1, size_r - 1, -1):
                    if l[i] != 0:
                        return 1
            if size_l < size_r:
                for i in range(size_r - 1, size_l - 1, -1):
                    if r[i] != 0:
                        return -1
            for i in range(min([size_l, size_r]) - 1, -1 , -1):
                if l[i] > r[i]:
                    return  1
                if l[i] < r[i]:
                    return -1
            return 0
        except Exception as e:
            raise

    def __display(self, l, r, s):
        """ Display

        :param list l
        :param list r
        :param int  s:-1 or 0 or 1
        """
        try:
            print("[LEFT] =")
            for i in range(self.D_L - 1, -1, -1):
                print(l[i], end="")
                if (self.D_L - i) % 10 == 0:
                    print(" ", end="")
                if (self.D_L - i) % 50 == 0:
                    print()
            print()
            print("[RIGHT] =")
            for i in range(self.D_R - 1, -1, -1):
                print(r[i], end="")
                if (self.D_R - i) % 10 == 0:
                    print(" ", end="")
                if (self.D_R - i) % 50 == 0:
                    print()
            print()
            # 大小比較結果
            sign = "=" if s == 0 else (">" if s > 0 else "<")
            print("[LEFT] {} [RIGHT]".format(sign))
        except Exception as e:
            raise


if __name__ == '__main__':
    try:
        obj = CompareBigDigits()
        obj.exec()
    except Exception as e:
        traceback.print_exc()
        sys.exit(1)