calc_v2.py

# -*- coding: utf-8 -*-
"""
Created on Sat Jan 07 12:00:41 2017

@author: Yunho
"""

def plus(a,b):
    print a+b
    return a+b

def minus(a,b):
    print a-b
    return a-b

def main(a,b):
    print '메인함수 입니다.'
    print '계산기에 오신걸 환영합니다'
    print '원하시는 계산을 선택하세요 1. 덧셈 2. 뺄셈'
    operation_opt = int(raw_input('enter opt: '))
    if operation_opt == 1:
        return plus(a,b)
    elif operation_opt == 2:
        return minus(a,b)
    else:
        print '잘못된 값을 입력하셨습니다.'

    
# __시스템예약어__
if __name__ == '__main__':
    while True:
        a = int(raw_input('enter num1: '))
        b = int(raw_input('enter num2: '))
        main(a,b)