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: PyCharmimport redef 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 = Nonefor 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 formulaprint("[结果]=", totle_res) return totle_res
def calc(formula): parentheses_flag = True calc_res = Nonewhile 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) )")
时间： 2024-08-03 21:14:53