作业：计算器开发
- 实现加减乘除及拓号优先级解析
- 用户输入 1 - 2 * ( (60-30 +(-40/5) * (9-2*5/3 + 7 /3*99/4*2998 +10 * 568/14 )) - (-4*3)/ (16-3*2) )等类似公式后，必须自己解析里面的(),+,-,*,/符号和公式，运算后得出结果，结果必须与真实的计算器所得出的结果一致
一、说明：
有一点bug就是不能计算幂次方,如:'6＊＊6'会报错
该计算器思路：
1、没用使用递归，先找出并计算所有括号里的公式，再计算乘除和加减2、所有的数字都认为是浮点型操作，以此来保留小数使用技术：1、正则表达式2、tkinter流程图：
代码如下：
#!/usr/bin/env python3#antuor:Alanimport refrom functools import reducefrom 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_dividenddef 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 = Falseif __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