Python script to compute Napier constant.

calc_napier.py

#! /usr/local/bin/python3.6
"""
Computation of Napier's constant
"""
import sys
import traceback


class CalcNapier:
    L  = 1000            # Digits of computation
    L1 = int(L / 8) + 1  # Length of list
    L2 = L1 + 1          # Length of list + 1
    N  = 451             # Number of items

    def compute(self):
        """ Computation of Napier's constant """
        try:
            s = [0 for _ in range(self.L2 + 1)]
            a = [0 for _ in range(self.L2 + 1)]
            s[0], a[0] = 1, 1
            for k in range(1, self.N + 1):
                a = self.__long_div(a, k)
                s = self.__long_add(s, a)
            self.__display(s)
        except Exception as e:
            raise

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

        :param  list a: integral values
        :param  list b: integral values
        :return list z: integral values
        """
        try:
            z = [0 for _ in range(self.N)]
            carry = 0
            for i in reversed(range(self.L2 + 1)):
                z[i] = a[i] + b[i] + carry
                if z[i] < 100000000:
                    carry = 0
                else:
                    z[i] -= 100000000
                    carry = 1
            return z
        except Exception as e:
            raise

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

        :param  list a: integral values
        :param  list b: integral values
        :return list z: integral values
        """
        try:
            z = [0 for _ in range(self.N)]
            r = 0
            for i in range(self.L2 + 1):
                w = a[i]
                z[i] = int(int(w + r) / b)
                r = ((w + r) % b) * 100000000
            return z
        except Exception as e:
            raise

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

        :param list s: integral values
        """
        try:
            print("{:7d}. ".format(s[0]), end="")
            for i in range(1, self.L1):
                print("{:08d} ".format(s[i]), end="")
            print()
        except Exception as e:
            raise


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