python正则表达式之作业计算器

#!/usr/bin/env python3
#antuor:Alan
 
import re
from functools import reduce
from tkinter import *
 
 
 
'''处理特殊－号运算'''
def minus_operation(expresstion):
  minus_operators = re.split("-",expresstion)
  calc_list = re.findall("[0-9]",expresstion)
  if minus_operators[0] =="":
    calc_list[0] = '-%s' % calc_list[0]
  res = reduce(lambda x,y:float(x)-float(y),calc_list)
  print(">>>>>>>>>>>>>>减号[%s]运算结果:" % expresstion,res)
  return res
 
'''reduce()对sequence连续使用function, 如果不给出initial, 则第一次调用传递sequence的两个元素,
以后把前一次调用的结果和sequence的下一个元素传递给function'''
 
 
 
 
'''处理双运算符号'''
def del_duplicates(expresstion):
  expresstion = expresstion.replace("++","+")
  expresstion = expresstion.replace("--","-")
  expresstion = expresstion.replace("+-","-")
  expresstion = expresstion.replace("--","+")
  expresstion = expresstion.replace('- -',"+")
  e
  return expresstion
 
'''＊／运算函数'''
def mutiply_dividend(expresstion):
  calc_list = re.split("[*/]",expresstion)     #用＊ or /分割公式
  operators = re.findall("[*/]",expresstion)    #找出所有＊和／号
  res = None
  for index,i in enumerate(calc_list):
    if res:
      if operators[index-1] =='*':
        res *= float(i)
      elif operators[index-1] =='/':
        res /=float(i)
    else :
      res = float(i)
  procession0 = "[%s]运算结果=" % expresstion,res
  final_result.insert(END,procession0)    #插入窗体
  print(procession0)
  return res
 
 
 
'''处理运算符号顺序混乱情况'''
def special_features(plus_and_minus_operators,multiply_and_dividend):
 
  for index,i in enumerate(multiply_and_dividend):
    i = i.strip()
    if i.endswith("*") or i.endswith("/"):
      multiply_and_dividend[index] = multiply_and_dividend[index] + plus_and_minus_operators[index] + multiply_and_dividend[index+1]
      del multiply_and_dividend[index+1]
      del plus_and_minus_operators[index]
  return plus_and_minus_operators,multiply_and_dividend
 
 
 
def minus_special(operator_list,calc_list):
  for index,i in enumerate(calc_list):
    if i =='':
      calc_list[index+1] = i + calc_list[index+1].strip()
 
 
 
'''运算除了（）的公式＋－＊／'''
def figure_up(expresstion):
  expresstion = expresstion.strip("()")    #去掉外面括号
  expresstion = del_duplicates(expresstion)  #去掉重复＋－号
  plus_and_minus_operators = re.findall("[+-]",expresstion)
  multiply_and_dividend = re.split("[+-]",expresstion)
  if len(multiply_and_dividend[0].strip()) ==0:
    multiply_and_dividend[1] = plus_and_minus_operators[0] + multiply_and_dividend[1]
    del multiply_and_dividend[0]
    del plus_and_minus_operators[0]
 
  plus_and_minus_operators,multiply_and_dividend = special_features(plus_and_minus_operators,multiply_and_dividend)
  for index,i in enumerate(multiply_and_dividend):
    if re.search("[*/]",i):
      sub_res = mutiply_dividend(i)
      multiply_and_dividend[index] = sub_res
 
  print(multiply_and_dividend,plus_and_minus_operators)  #计算
  final_res = None
  for index,item in enumerate(multiply_and_dividend):
    if final_res:
      if plus_and_minus_operators[index-1] == '+':
        final_res += float(item)
      elif plus_and_minus_operators[index-1] == '-':
        final_res -= float(item)
    else:
      final_res = float(item)
  procession = '[%s]计算结果:' % expresstion,final_res
  final_result.insert(END,procession)    #插入窗体
  print(procession)
  return final_res
 
"""主函数：运算逻辑：先计算拓号里的值,算出来后再算乘除,再算加减"""
def calculate():
  expresstion = expresstions.get()         #获取输入框值
  flage = True
  calculate_res = None               #初始化计算

结果为None while flage: m = re.search("\([^()]*\)",expresstion) #先找最里层的（） # pattern = re.compile(r"\([^()]*\)") # m = pattern.match(expresstion) if m: sub_res = figure_up(m.group()) #运算（）里的公式 expresstion = expresstion.replace(m.group(),str(sub_res)) #运算完毕把结果替换掉公式 else: print('---------------括号已经计算完毕--------------') procession1 = "最终计算结果:",figure_up(expresstion) final_result.insert(END,procession1) #插入窗体 print('\033[31m最终计算结果:',figure_up(expresstion)) flage = False if __name__=="__main__": # res = calculate("1 - 2 * ( (60-30 +(-40/5) * (9-2*5/3 + 7 /3*99/4*2998 +10 * 568/14 )) - (-4*3)/ (16-3*2) )") window = Tk() ###创建窗体 window.title('计算器') ###命名窗体 frame1 = Frame(window) ###框架1 frame1.pack() ###放置 frame2 = Frame(window) ###框架2 frame2.pack() ###放置 lable = Label(frame1,text = "请输入公式：") ###文字标签 lable.pack() expresstions = StringVar() ###输入框属性，字符串 entryname = Entry(frame1,textvariable = expresstions) ###文本输入框 bt_get_expresstions = Button(frame1,text = "提交",command = calculate) ###按钮挂件 bt_get_expresstions.pack() entryname.pack() lable.grid(row =1,column =1) ###位置 entryname.grid(row=1,column =2) bt_get_expresstions.grid(row =1,column =3) final_result = Text(frame2) ###计算结果显示框 final_result.tag_config("here", background="yellow", foreground="blue") final_result.pack() window.mainloop() ###事件循环

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