python练习题之简易计算器

print("简易计算器：(+-*/,例如1+2)")
while True:
    str=input("请输入含两个数的表达式或者Q退出>>：")
    if(str=="Q"):
        break
    else:
        if("+" in str ):
            aa=str.split("+")
            print(aa)
            a1=int(aa[0])
            a2=int(aa[1])
            print("表达式",str,"的计算结果是：",a1+a2,"\n")
        elif ("-" in str ):
            aa=str.split("-")
            a1=int(aa[0])
            a2=int(aa[1])
            print("表达式",str,"的计算结果是：",a1-a2,"\n")
        elif ("/" in str ):
            aa=str.split("/")
            a1=int(aa[0])
            a2=int(aa[1])
            print("表达式",str,"的计算结果是：",a1/a2,"\n")
        elif ("*" in str):
            aa=str.split("*")
            a1=int(aa[0])
            a2=int(aa[1])
            print("表达式",str,"的计算结果是：",a1*a2,"\n")
        else:
            print("输入格式不对，请重新输入！","\n")