inner = re.search("\([^()]*\)", calc_input)

def del_double(str):
  str = str.replace("++", "+")
  str = str.replace("--", "-")
  str = str.replace("+-","-")
  str = str.replace("- -","-")
  str = str.replace("+ +","+")
  return str

calc_input = calc_input.replace(inner.group(), str(ret))

#!/usr/bin/env python3.5
# -*-coding:utf8-*-
import re
a =r'1 - 2 * ( (60-30 +(-40/5) * (9-2*5/3 + 7 /3*99/4*2998 +10 * 568/14 ))- (-4*3)/(16-3*2))'
# ＊／運(yùn)算函數(shù)
def shengchu(str):
  calc = re.split("[*/]",str)   #用＊/分割公式
  OP = re.findall("[*/]",str)  #找出所有＊和／號(hào)
  ret = None
  for index,i in enumerate(calc):
    if ret:
      if OP[index-1] == "*":
        ret *= float(i)
      elif OP[index-1] == "/":
        ret /= float(i)
    else:
      ret = float(i)
  return ret
# 去掉重復(fù)運(yùn)算,和處理特列+－符號(hào)
def del_double(str):
  str = str.replace("++", "+")
  str = str.replace("--", "-")
  str = str.replace("+-","-")
  str = str.replace("- -","-")
  str = str.replace("+ +","+")
  return str
# 計(jì)算主控制函數(shù)
def calc_contrl(str):
  tag = False
  str = str.strip("()") # 去掉最外面的括號(hào)
  str = del_double(str) # 調(diào)用函數(shù)處理重復(fù)運(yùn)算
  find_ = re.findall("[+-]",str) # 獲取所有+－ 操作符
  split_ = re.split("[+-]",str) #正則處理 以+－操作符進(jìn)行分割，分割后 只剩*/運(yùn)算符
  if len(split_[0].strip()) == 0: # 特殊處理
    split_[1] = find_[0] + split_[1] # 處理第一個(gè)數(shù)字前有“－”的情況，得到新的帶符號(hào)的數(shù)字
    # 處理第一個(gè)數(shù)字前為負(fù)數(shù)“-"，時(shí)的情況，可能后面的操作符為“－”則進(jìn)行標(biāo)記
    if len(split_) == 3 and len(find_) ==2:
      tag =True
      del split_[0] # 刪除原分割數(shù)字
      del find_[0]
    else:
      del split_[0] # 刪除原分割數(shù)字
      del find_[0] # 刪除原分割運(yùn)算符
  for index, i in enumerate(split_):
    # 去除以*或/結(jié)尾的運(yùn)算數(shù)字
    if i.endswith("* ") or i.endswith("/ "):
      split_[index] = split_[index] + find_[index] + split_[index+1]
      del split_[index+1]
      del find_[index]
  for index, i in enumerate(split_):
    if re.search("[*/]",i): # 先計(jì)算含*/的公式
      sub_res = shengchu(i) #調(diào)用剩除函數(shù)
      split_[index] = sub_res
  # 再計(jì)算加減
  res = None
  for index, i in enumerate(split_):
    if res:
      if find_[index-1] == "+":
        res += float(i)
      elif find_[index-1] == "-":
        # 如果是兩個(gè)負(fù)數(shù)相減則將其相加，否則相減
        if tag == True:
          res += float(i)
        else:
          res -= float(i)
    else:
      # 處理沒(méi)有括號(hào)時(shí)會(huì)出現(xiàn)i 為空的情況
      if i != "":
        res = float(i)
  return res
if __name__ == '__main__':
  calc_input = input("請(qǐng)輸入計(jì)算公式，默認(rèn)為:%s：" %a).strip()
  try:
    if len(calc_input) ==0:
      calc_input = a
    calc_input = r'%s'%calc_input # 做特殊處理，保持字符原形
    flag = True  # 初始化標(biāo)志位
    result = None  # 初始化計(jì)算結(jié)果
    # 循環(huán)處理去括號(hào)
    while flag:
      inner = re.search("\([^()]*\)", calc_input)# 先獲取最里層括號(hào)內(nèi)的單一內(nèi)容
      #print(inner.group())
      # 有括號(hào)時(shí)計(jì)算
      if inner:
        ret = calc_contrl(inner.group()) # 調(diào)用計(jì)算控制函數(shù)
        calc_input = calc_input.replace(inner.group(), str(ret)) # 將運(yùn)算結(jié)果，替換原處理索引值處對(duì)應(yīng)的字符串
        print("處理括號(hào)內(nèi)的運(yùn)算[%s]結(jié)果是：%s" % (inner.group(),str(ret)))
        #flag = True
      # 沒(méi)有括號(hào)時(shí)計(jì)算
      else:
        ret = calc_contrl(calc_input)
        print("最終計(jì)算結(jié)果為：%s"% ret)
        #結(jié)束計(jì)算標(biāo)志
        flag = False
  except:
    print("你輸入的公式有誤請(qǐng)重新輸入！")