Python script to compute big-digit values.(v2)

calc_big_digits_2.py

#! /usr/local/bin/python3.6
"""
Computation of big-digit values (Ver.2)
"""
import random
import sys
import traceback


class CalcBigDigits:
    N_A = 1000
    N_B = 996
    LIMIT = 4
    RANGE = 10**LIMIT
    SIZE_A = int((N_A-1) / LIMIT) + 1
    SIZE_B = int((N_B-1) / LIMIT) + 1

    def __init__(self):
        self.a = [random.randrange(self.RANGE) for _ in range(self.SIZE_A)]
        self.b = [random.randrange(self.RANGE) for _ in range(self.SIZE_B)]
        self.c =  random.randrange(self.RANGE)
        print("A =")
        self.__display(self.a)
        print("B =")
        self.__display(self.b)
        print("C =\n{:04d}\n\n".format(self.c))

    def compute_add(self):
        """ Addition """
        try:
            print("A + B =")
            self.__display(self.__long_add(self.a, self.b))
        except Exception as e:
            raise

    def compute_sub(self):
        """ Subtraction """
        try:
            print("A - B =")
            self.__display(self.__long_sub(self.a, self.b))
        except Exception as e:
            raise

    # 計算 ( 乗算 )
    def compute_mul(self):
        """ Multiplication """
        try:
            print("A * C =")
            self.__display(self.__long_mul(self.a, self.c))
        except Exception as e:
            raise

    # 計算 ( 除算 )
    def compute_div(self):
        """ Division """
        try:
            print("A / C =")
            self.__display(self.__long_div(self.a, self.c))
        except Exception as e:
            raise

    def __long_add(self, a, b):
        """ Computation of long + long

        :param  list a
        :param  list b
        :return list z
        """
        try:
            z = [0 for _ in range(max(len(a), len(b)) + 1)]
            for i in range(len(a)):
                z[i] = a[i]
            for i in range(len(b)):
                z[i] += b[i]
                if z[i] >= 10**self.LIMIT:
                    z[i] -= 10**self.LIMIT
                    z[i + 1] += 1
            return z
        except Exception as e:
            raise

    def __long_sub(self, a, b):
        """ Computation of long - long

        :param  list a
        :param  list b
        :return list z
        """
        try:
            z = [0 for _ in range(max(len(a), len(b)))]
            for i in range(len(a)):
                z[i] = a[i]
            for i in range(len(b)):
                z[i] -= b[i]
                if z[i] < 0:
                    z[i] += 10**self.LIMIT
                    z[i + 1] -= 1
            return z
        except Exception as e:
            raise

    def __long_mul(self, a, c):
        """ Computation of long * short

        :param  list a
        :param  list b
        :return list z
        """
        try:
            z = [0 for _ in range(len(a) + 1)]
            for i in range(len(a)):
                z[i] += a[i] * c
                if z[i] >= 10**self.LIMIT:
                    z[i + 1] += int(z[i] / 10**self.LIMIT)
                    z[i] %= 10**self.LIMIT
            return z
        except Exception as e:
            raise

    def __long_div(self, a, c):
        """ Computation of long / short

        :param  list a
        :param  list b
        :return list z
        """
        try:
            z = [0 for _ in range(len(a))]
            for i in reversed(range(len(a))):
                z[i] += int(a[i] / c)
                if i > 0:
                    a[i - 1] += (a[i] % c) * 10**self.LIMIT
            return z
        except Exception as e:
            raise

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

        :param  list s
        """
        try:
            size = len(s)
            if s[size - 1] == 0:
                size -= 1
            for i in reversed(range(size)):
                print("{:04d} ".format(s[i]), end="")
                if (size - i) % 10 == 0 and i != 0:
                    print()
            print("\n")
        except Exception as e:
            raise


if __name__ == '__main__':
    try:
        obj = CalcBigDigits()
        obj.compute_add()
        obj.compute_sub()
        obj.compute_mul()
        obj.compute_div()
    except Exception as e:
        traceback.print_exc()
        sys.exit(1)