python3 正则表达式 re模块之辣眼睛 计算器

额。。。学到几个常用模块了，也要其中考试了，每天晚上敲一点，敲得脑壳疼，不过又想到好一点的办法了，有时间再改吧。

此非吾所欲也，实属无奈也。。。。复习之路漫漫，吾将到书上求索，在此不多逗留，我挥一挥衣袖，留下一段惨不忍睹的代码，且不带走一片云彩。

 #!usr/bin/env/ python
 # -*- coding:utf-8 -*-
 # Author: XiaoFeng
 import re

 a = '1 - 2 * ( ( 6 0 -3 0  +(-40/5) * (9-2*5/3 + 7 /3*99/4*2998 +10 * 568/14 )) - (-4*3)/ (16-3*2) )'
 a_new = re.sub(" ", "", a)
 print(a_new)
 ret = re.findall(r"\([^()]*\)", a_new)
 while ret:
     ret = re.findall(r"\([^()]*\)", a_new)
     print(ret)
     for element in ret:
         formula = element
         formula = formula.replace("(", "")
         formula = formula.replace(")", "")
         # print(formula)
         for i in formula:
             if "--" in formula:
                 formula = formula.replace("--", "+")
             elif "*" == i:
                 handle = re.search(r"[-+]?\d+\.?\d*\*[-+]?\d+\.?\d*", formula)
                 if handle:
                     handle_list = handle.group()
                 else:
                     continue
                 handle_a, handle_b = re.findall(r"[-+]?\d+\.?\d*", handle_list)
                 if "." in handle_a or "." in handle_b:
                     result = float(handle_a) * float(handle_b)
                     if result >= 0:
                         result = "+" + str(result)
                     result = str(result)
                 else:
                     result = int(handle_a) * int(handle_b)
                     if result >= 0:
                         result = "+" + str(result)
                     result = str(result)
                 formula = formula.replace(handle_list, result)
                 # print(formula)
             elif "/" == i:
                 handle = re.search(r"[-+]?\d+\.?\d*/[-+]?\d+\.?\d*", formula)
                 if handle:
                     handle_list = handle.group()
                 else:
                     continue
                 handle_a, handle_b = re.findall(r"[-+]?\d+\.?\d*", handle_list)
                 if "." in handle_a or "." in handle_b:
                     result = float(handle_a) / float(handle_b)
                     if result >= 0:
                         result = "+" + str(result)
                     result = str(result)
                 else:
                     result = int(handle_a) / int(handle_b)
                     if result >= 0:
                         result = "+" + str(result)
                     result = str(result)
                 formula = formula.replace(handle_list, result)
                 # print(formula)
         for i in formula:
             if "--" in formula:
                 formula = formula.replace("--", "+")
             elif "+" == i:
                 handle = re.search(r"[-+]?\d+\.?\d*\+[-+]?\d+\.?\d*", formula)
                 if handle:
                     handle_list = handle.group()
                 else:
                     continue
                 handle_a, handle_b = re.findall(r"[-+]?\d+\.?\d*", handle_list)
                 if "." in handle_a or "." in handle_b:
                     result = float(handle_a) + float(handle_b)
                     if result >= 0:
                         result = "+" + str(result)
                     result = str(result)
                 else:
                     result = int(handle_a) + int(handle_b)
                     if result >= 0:
                         result = "+" + str(result)
                     result = str(result)
                 formula = formula.replace(handle_list, result)
                 # print(formula)
             elif "-" == i:
                 handle = re.search(r"[-+]?\d+\.?\d*-[-+]?\d+\.?\d*", formula)
                 if handle:
                     handle_list = handle.group()
                 else:
                     continue
                 handle_a, handle_b = re.findall(r"[-+]?\d+\.?\d*", handle_list)
                 if "." in handle_a or "." in handle_b:
                     result = float(handle_a) + float(handle_b)
                     if result >= 0:
                         result = "+" + str(result)
                     result = str(result)
                 else:
                     result = int(handle_a) + int(handle_b)
                     if result >= 0:
                         result = "+" + str(result)
                     result = str(result)
                 formula = formula.replace(handle_list, result)
                 # print(formula)
         # print(formula)
         # print(element)
         a_new = a_new.replace(element, formula)
         # print(a_new)
     print("------------")
 print(a_new)
 formula = a_new
 for i in formula:
     if "--" in formula:
         formula = formula.replace("--", "+")
     elif "*" == i:
         handle = re.search(r"[-+]?\d+\.?\d*\*[-+]?\d+\.?\d*", formula)
         if handle:
             handle_list = handle.group()
         else:
             continue
         handle_a, handle_b = re.findall(r"[-+]?\d+\.?\d*", handle_list)
         if "." in handle_a or "." in handle_b:
             result = float(handle_a) * float(handle_b)
             if result >= 0:
                 result = "+" + str(result)
             result = str(result)
         else:
             result = int(handle_a) * int(handle_b)
             if result >= 0:
                 result = "+" + str(result)
             result = str(result)
         formula = formula.replace(handle_list, result)
         print(formula)
     elif "/" == i:
         handle = re.search(r"[-+]?\d+\.?\d*/[-+]?\d+\.?\d*", formula)
         if handle:
             handle_list = handle.group()
         else:
             continue
         handle_a, handle_b = re.findall(r"[-+]?\d+\.?\d*", handle_list)
         if "." in handle_a or "." in handle_b:
             result = float(handle_a) / float(handle_b)
             if result >= 0:
                 result = "+" + str(result)
             result = str(result)
         else:
             result = int(handle_a) / int(handle_b)
             if result >= 0:
                 result = "+" + str(result)
             result = str(result)
         formula = formula.replace(handle_list, result)
         print(formula)
 print("=========")
 for i in formula:
     if "--" in formula:
         formula = formula.replace("--", "+")
     elif "+" == i:
         handle = re.search(r"[-+]?\d+\.?\d*\+[-+]?\d+\.?\d*", formula)
         if handle:
             handle_list = handle.group()
         else:
             continue
         handle_a, handle_b = re.findall(r"[-+]?\d+\.?\d*", handle_list)
         if "." in handle_a or "." in handle_b:
             result = float(handle_a) + float(handle_b)
             if result >= 0:
                 result = "+" + str(result)
             result = str(result)
         else:
             result = int(handle_a) + int(handle_b)
             if result >= 0:
                 result = "+" + str(result)
             result = str(result)
         formula = formula.replace(handle_list, result)
         print(formula)
     elif "-" == i:
         handle = re.search(r"[-+]?\d+\.?\d*-[-+]?\d+\.?\d*", formula)
         if handle:
             handle_list = handle.group()
         else:
             continue
         handle_a, handle_b = re.findall(r"[-+]?\d+\.?\d*", handle_list)
         if "." in handle_a or "." in handle_b:
             result = float(handle_a) + float(handle_b)
             if result >= 0:
                 result = "+" + str(result)
             result = str(result)
         else:
             result = int(handle_a) + int(handle_b)
             if result >= 0:
                 result = "+" + str(result)
             result = str(result)
         formula = formula.replace(handle_list, result)
         print(formula)