作业要求：
去掉括号，计算式子结果.
1 - 2 * ( (60-30 +(-9-2-5-2*3-5/3-40*4/2-3/5+6*3) * (-9-2-5-2*5/3 + 7 /3*99/4*2998 +10 * 568/14 )) - (-4*3)/ (16-3*2) )
#!/usr/bin/env python
# -*- coding: utf-8 -*-
# @Time : 2017/4/30 7:44
# @Author : Olivia Su
# @File : 作业.py
# @Software: PyCharm
import re
def deal_negative_issue(calc_list):
new_calc_list=[] #定义一个新的空列表，后面筛选完成后将数据放入新列表中
for index,item in enumerate(calc_list):
if item.strip().endswith("*") or item.strip().endswith("/"): #挑选出以乘号或除号结尾的字符串
new_calc_list.append("%s-%s"%(calc_list[index],calc_list[index+1])) #拼接字符串 处理类似2*5/-3
# elif ("*" or "/") in item: #找出列表中的有乘除的选项，这种写法我试了好像只匹配*在，单独40/5这种匹配不出来
elif ("/") in item or ("*") in item:
print(item)
new_calc_list.append(item)
print("new_calc_ist",new_calc_list)
return new_calc_list
def deal_unusual_issue(formula):
formula = formula.replace("++","+")
formula = formula.replace("+-", "-")
formula = formula.replace("-+", "-")
formula = formula.replace("--", "+")
formula = formula.replace("- -", "+")
return formula
def addition_and_subtraction(formula):
sub_calc_list = re.split("[+-]",formula)
sub_operator_list = re.findall("[+-]",formula)
print(type(sub_calc_list), sub_operator_list)
totle_res = None
for index,i in enumerate(sub_calc_list):
if totle_res: #sub_res为真，表示这不是第一次循环
if sub_operator_list[index-1]=="+": #通过sub_operator_list中的index判断到底是加法还是减法
totle_res += float(i)
else:
totle_res -= float(i)
else:
sub_res = float(i)
print(totle_res)
def calculating(formula):
print("运算",formula)
calc_list = re.split("[+-]",formula) #通过+-符号将各个乘除运算分隔出来
calc_list = deal_negative_issue(calc_list)
print(calc_list)
for item in calc_list:
sub_calc_list = re.split("[*/]",item)
sub_operator_list = re.findall("[*/]",item) #将乘号除号通过列表方式分隔出来
print(sub_calc_list,sub_operator_list)
sub_res = None
for index,i in enumerate(sub_calc_list):
if sub_res: #sub_res为真，表示这不是第一次循环
if sub_operator_list[index-1]=="*": #通过sub_operator_list中的index判断到底是加法还是减法，
sub_res *= float(i)
else:
sub_res /= float(i)
else:
sub_res = float(i)
print("[%s]="%item,sub_res)
formula = formula.replace(item,str(sub_res))
formula = deal_unusual_issue(formula)
print(formula)
#计算+-法
totle_calc_list = re.split("[+-]", formula)
totle_operator_list = re.findall("[+-]", formula) # 将乘号除号通过列表方式分隔出来
print(totle_calc_list, totle_operator_list)
totle_res = None
for index,item in enumerate(totle_calc_list):
if totle_res: #sub_res为真，表示这不是第一次循环
if totle_operator_list[index-1]=="+": #通过sub_operator_list中的index判断到底是加法还是减法，
totle_res += float(item)
else:
totle_res -= float(item)
else:
totle_res = float(item)
# return formula
print("[结果]=", totle_res)
return totle_res
def calc(formula):
parentheses_flag = True
calc_res = None
while parentheses_flag:
m = re.search("\([^()]*\)",formula) #找出最底层的括号，一个一个找
print(m)
if m:
# print(type(m.group()))
subformula = m.group().strip("()") #把找出来的括号剥离
subres = calculating(subformula)
formula = formula.replace(m.group(),str(subres))
else:
print("没括号了")
print("最终结果为",calculating(formula))
parentheses_flag = False
if __name__ =="__main__":
res = calc("1 - 2 * ( (60-30 +(-9-2-5-2*3-5/3-40*4/2-3/5+6*3) * (-9-2-5-2*5/3 + 7 /3*99/4*2998 +10 * 568/14 )) - (-4*3)/ (16-3*2) )")
