python 计算器

开发一个简单的python计算器

1. 实现加减乘除及拓号优先级解析
2. 用户输入 1 - 2 * ( (60-30 +(-40/5) * (9-2*5/3 + 7 /3*99/4*2998 +10 * 568/14 )) - (-4*3)/ (16-3*2) )等类似公式后，必须自己解析里面的(),+,-,*,/符号和公式(不能调用eval等类似功能偷懒实现)，运算后得出结果，结果必须与真实的计算器所得出的结果一致

# 编辑者：闫龙
import re #导入re模块(正则表达式)
calc2 = "1-2*(( 60-30+(-40/52)*(9-2*5/3+7/3*-99/4*2998+10*568/14))-(-4*3)/(16-3*2))"
calc1 = "1-2*((60-30+(-40/5)*(9-2*5/3+7/3*99/4*2998+10*568/14))-(-4*3)/(16-3*2))"
calc = "1-2*((-60*-30+(-40 /-5)*(9*2*5/3+7/3*99/4*2998+10*568/14))-(-4*32)/(16-3*2))"
def Format(Str):
    "格式化运算式"
    Str = Str.replace(" ","")
    Str = Str.replace("+-","-")
    Str = Str.replace("-+", "-")
    Str = Str.replace("++", "+")
    Str = Str.replace("--", "+")
    return Str
def SumCut(Str):
    while re.search("-?[0-9]+\.?[0-9]*[-+][0-9]+\.?[0-9]*",Str):
        newRes= re.search("-?[0-9]+\.?[0-9]*[-+][0-9]+\.?[0-9]*",Str)
        WhatIs = newRes.group()
        if(WhatIs.find("-") > 0):
            l = WhatIs.split("-")
            Str = Str.replace(WhatIs,str(float(l[0])-float(l[1])))
        elif(WhatIs.find("+") > 0):
            l = WhatIs.split("+")
            Str = Str.replace(WhatIs,str(float(l[0])+float(l[1])))
    return Str.replace("(","").replace(")","")
def MulDiv(Str):
    while re.search("-?[0-9]+\.?[0-9]*[/*].?[0-9]+\.?[0-9]*",Str):
        newRes= re.search("-?[0-9]+\.?[0-9]*[/*].?[0-9]+\.?[0-9]*",Str)
        WhatIs = newRes.group()
        if(WhatIs.find("/") > 0):
            l = WhatIs.split("/")
            Str = Str.replace(WhatIs,str(float(l[0])/float(l[1])))
        elif(WhatIs.find("*") > 0):
            l = WhatIs.split("*")
            if(float(l[0])<0 and float(l[1])<0):
              Str = Str.replace(WhatIs, "+"+str(float(l[0]) * float(l[1])))
            else:
              Str = Str.replace(WhatIs,str(float(l[0])*float(l[1])))
    return Format(Str)
while re.search("\([^()]+\)",calc):
    res = re.search("\([^()]+\)", calc)
    resTwo = MulDiv(Format(res.group()))
    resTwo = SumCut(resTwo)
    calc = calc.replace(res.group(),resTwo)
else:
    resTwo = MulDiv(calc)
    resTwo = SumCut(resTwo)
    calc = resTwo
print(calc)