python终端计算器，还有没其他方法？

import sys
def lt(a, b, c ):
    if b == "+":
        return int(a)+int(c)
    elif b == "-":
        return int(a)-int(c)
    elif b == "*":
        return int(a)*int(c)
    elif b == "/":
        return int(a)/int(c)
print(lt(sys.argv[1],sys.argv[2],sys.argv[-1]))