python 四则运算器

#_*_coding:utf-8_*_

#两个操作数和一个操作符的计算器，加减乘除取余幂  + - * / % **

'''
def yunsuan(num1,sym,num2):
    
    symbol = ['+','-','*','/','%','**']

    if sym==symbol[0]:
        return num1+num2
    elif sym==symbol[1]:
        return num1-num2
    elif sym==symbol[2]:
        return num1*num2
    elif sym==symbol[3]:
        return num1/num2
    elif sym==symbol[4]:
        return num1%num2
    elif sym==symbol[5]:
        return num1**num2
        
        
num1 = int(raw_input('请输入第一个操作数\n>'))
sym = raw_input('请输入操作符\n>')
num2 = int(raw_input('请输入第二个操作数\n>'))

result = yunsuan(num1,sym,num2)
print result
'''

def yunsuan(exp):
    symbol = ['+','-','*','/','%','**']
    yx = ''
    for i in symbol:
        if i in exp:
            yx = i
    if yx == '':
        return 'exp is error!!'
        
    num = exp.split(yx)
    
    if '.' in num[0] or '.' in num[1]:
        num[0] =float(num[0])
        num[1] =float(num[1])
    else:
        num[0] =int(num[0])
        num[1] =int(num[1])
        
    if yx==symbol[0]:
        return num[0]+num[1]
    elif yx==symbol[1]:
        return num[0]-num[1]
    elif yx==symbol[2]:
        return num[0]*num[1]
    elif yx==symbol[3]:
        return num[0]/num[1]
    elif yx==symbol[4]:
        return num[0]%num[1]
    elif yx==symbol[5]:
        return num[0]**num[1]


exp = raw_input('请输入一个表达式\n>')
result = yunsuan(exp)
print result