A Python cmd.Cmd console supporting arithmetic operations

calc_console.py

import cmd
import shlex
import operator
from functools import reduce

class CalcConsole(cmd.Cmd):
    """ A console that helps to perform regular arithmetic """

    prompt = "Calc> "

    def _parse(self, line):
        """ Parse an input line and return items """

        items = shlex.split(line)
        try:
            try:
                # Try pure int first
                nums = [int(i) for i in items]
            except:
                # Fallback to float
                nums = [float(i) for i in items]
        except Exception as ex:
            print(f"error parsing arguments - {ex}")
            return []
        
        return nums

    def do_add(self, arg):
        """ Implement addition """

        nums = self._parse(arg)
        print(sum(nums))

    def do_prod(self, arg):
        """ Implement multiplication """

        nums = self._parse(arg)
        print(reduce(operator.mul, nums))

    def do_div(self, arg):
        """ Implement division """

        # Only allow two operators
        items = self._parse(arg)
        if len(items) != 2:
            print('usage: div <dividend> <divisor>')
            return
        if items[1] == 0:
            print('division by zero not allowed')
            return
        
        print(items[0]/items[1])

    def default(self, arg):
        """ Allow console generic arithmetic using eval """
        try:
            print(eval(arg))
        except Exception as ex:
            print(f"error evaluating {arg} : {ex}")
    
    def do_EOF(self, line):
        return True