# !/usr/bin/env python
# -*- coding:utf-8 -*-
# Author:lzdimport redef main():while True:a=input("请输入你想计算的数学方程式，先小括号（请输入半角的括号，不要输入中文的），后加减乘除\n")#a=' 1 - 2 * ( (60-30 +(-40/5) * (9-2*5/3 + 7 /3*99/4*2998 +10 * 568/14 )) - (-4*3)/ (16-3*2) )'a = a.replace(' ', '')# print(a)if re.search(r"[0-9\+\-\*/()\.]+", a) == None:print("匹配失败，输入格式错误，请重新输入\n")continueelif a.count('(') != a.count(')'):print('你写的括号左右个数不匹配')continueelif len(re.search(r"[0-9\+\-\*/()\.]+", a).group()) != len(a):print("输入格式错误，请重新输入\n")continueelse:while True:if '(' in a:ct = re.search(r'\([^()]+\)', a) #计算出第一个()里的算式if ct is not None:b = ct.group()c = chengfa_chufa(b)a = re.sub(r'\(([^()]+)\)', str(c), a, 1)print(a)else:c = chengfa_chufa(a)print(c)breakbreakdef jiajianfa(a):'''计算加减法:param::return:'''if '--' in a:a = a.replace('--', '+')c = re.findall(r'-?\d+\.?\d*', a) #-123456.132123ls = []for i in c:ls.append(float(i))rest = sum(ls)return restdef chengfa(a):'''计算乘法:param ct::return:'''b = re.search(r'\d+\.?\d*(\*-?\d+\.?\d*)+', a)  #132132.654645*-564564.456456*-5645645.654561651615if b is not None:b = b.group()rest = 1c = re.findall(r'-?\d+\.?\d*', b)ls = []for item in c:ls.append(float(item))for i1 in range(len(ls)):rest = rest * ls[i1]a = re.sub(r'\d+\.?\d*(\*-?\d+\.?\d*)+', str(rest), a, 1)return adef chufa(a):'''计算出发:param a::return:'''b = re.search(r'\d+\.?\d*(\/-?\d+\.?\d*)+', a) #523.5564561/-1231.564564/-1344.4546if b is not None:b = b.group()c = re.findall(r'-?\d+\.?\d*', b)ls = []for i in c:ls.append(float(i))rest = ls[0]for i1 in range(1, len(ls)):rest = rest / ls[i1]a = re.sub(r'\d+\.?\d*(\/-?\d+\.?\d*)+', str(rest), a, 1)return adef chengfa_chufa(b):'''计算结果:return:'''while True:if '*' in b:c = b.split('*')if '/' in c[0]:b = chufa(b)else:b = chengfa(b)elif '/' in b:b = chufa(b)elif '+' or '-' in b:b = jiajianfa(b)return belse:return bmain()