class Counter: 
 #引入tkinter 
 import tkinter as tk 
 #引入消息彈窗模塊 
 import tkinter.messagebox as mbox 
 
 #初始化Counter 
 def __init__(self): 
 #生成一個(gè)窗口對(duì)象 
 self.window = self.tk.Tk() 
 #命名窗口對(duì)象的顯示title 
 self.window.title('計(jì)算器') 
 #設(shè)置窗口的大小 
 self.window.minsize(240, 325) 
 self.window.maxsize(240, 325) 
 #是否清空顯示框判定參數(shù) 
 self.is_init_lable = False 
 #設(shè)置菜單 
 self.set_menu() 
 #設(shè)置顯示框 
 self.lable_show = self.tk.Label(text='', anchor='se', font=('黑體', 30), fg='black') 
 self.lable_show.place(x=0, y=0, width=240, height=80) 
 #設(shè)置按鈕組件 
 self.set_buttons() 
 #將窗口放入主消息隊(duì)列 
 self.window.mainloop() 
 
 #設(shè)置菜單 
 def set_menu(self): 
 #創(chuàng)建總菜單 
 menubar = self.tk.Menu(self.window) 
 #創(chuàng)建一個(gè)下拉菜單，并且加入文件菜單 
 filemenu = self.tk.Menu(menubar, tearoff=0) 
 #創(chuàng)建下來(lái)菜單的選項(xiàng) 
 filemenu.add_command(label="退出計(jì)算器", command=self.window.quit) 
 #print author的函數(shù) 
 def show_author(): 
  self.mbox.showinfo(message='Wiz333@XDL 2017') 
 filemenu.add_command(label="作者", command=show_author) 
 #將文件菜單作為下拉菜單添加到總菜單中，并且將命名為操作 
 menubar.add_cascade(label="操作", menu=filemenu) 
 #顯示總菜單 
 self.window.config(menu=menubar) 
 
 #設(shè)置按鈕組件 
 def set_buttons(self): 
 #7 
 btn7 = self.tk.Button(text='7', bd=2, font='黑體') 
 btn7.place(x=0, y=90, width=60, height=40) 
 #8 
 btn8 = self.tk.Button(text='8', bd=2, font='黑體') 
 btn8.place(x=60, y=90, width=60, height=40) 
 #9 
 btn9 = self.tk.Button(text='9', bd=2, font='黑體') 
 btn9.place(x=120, y=90, width=60, height=40) 
 #+ 
 btn_jia = self.tk.Button(text='+', bd=2, font='黑體') 
 btn_jia.place(x=180, y=90, width=60, height=40) 
 #4 
 btn4 = self.tk.Button(text='4', bd=2, font='黑體') 
 btn4.place(x=0, y=130, width=60, height=40) 
 #5 
 btn5 = self.tk.Button(text='5', bd=2, font='黑體') 
 btn5.place(x=60, y=130, width=60, height=40) 
 #6 
 btn6 = self.tk.Button(text='6', bd=2, font='黑體') 
 btn6.place(x=120, y=130, width=60, height=40) 
 #- 
 btn_jian = self.tk.Button(text='-', bd=2, font='黑體') 
 btn_jian.place(x=180, y=130, width=60, height=40) 
 #1 
 btn1 = self.tk.Button(text='1', bd=2, font='黑體') 
 btn1.place(x=0, y=170, width=60, height=40) 
 #2 
 btn2 = self.tk.Button(text='2', bd=2, font='黑體') 
 btn2.place(x=60, y=170, width=60, height=40) 
 #3 
 btn3 = self.tk.Button(text='3', bd=2, font='黑體') 
 btn3.place(x=120, y=170, width=60, height=40) 
 #* 
 btn_cheng = self.tk.Button(text='*', bd=2, font='黑體') 
 btn_cheng.place(x=180, y=170, width=60, height=40) 
 #0 
 btn0 = self.tk.Button(text='0', bd=2, font='黑體') 
 btn0.place(x=0, y=210, width=120, height=40) 
 #. 
 btn_point = self.tk.Button(text='.', bd=2, font='黑體') 
 btn_point.place(x=120, y=210, width=60, height=40) 
 #/ 
 btn_chu = self.tk.Button(text='/', bd=2, font='黑體') 
 btn_chu.place(x=180, y=210, width=60, height=40) 
 #取消 
 btn_cancel = self.tk.Button(text='C', bd=2, font='黑體') 
 btn_cancel.place(x=0, y=250, width=60, height=40) 
 #確定 
 btn_ok = self.tk.Button(text='=', bd=2, font='黑體') 
 btn_ok.place(x=60, y=250, width=180, height=40) 
 #綁定Button的點(diǎn)擊事件 
 btn7.bind_class('Button', '<Button-1>', self.click_button) 
 
 #綁定Button的點(diǎn)擊事件 
 def click_button(self,e): 
 #判斷是否是新的運(yùn)算,如果是則清空顯示框 
 if self.is_init_lable: 
  self.lable_show['text'] = '' 
  self.is_init_lable = False 
 #label_show顯示的累加 
 font = e.widget['text'] 
 self.lable_show['text'] += font 
 #異常捕獲 
 try: 
  #判定運(yùn)算符號(hào)重復(fù)的時(shí)候,使用最后輸入的符號(hào) 
  if self.lable_show['text'][-1] in ['+','-','*','/'] and self.lable_show['text'][-2] in ['+','-','*','/']: 
  header = self.lable_show['text'][:-2] 
  footer = self.lable_show['text'][-1] 
  self.lable_show['text'] = header+footer 
 except: 
  pass 
 
 #普通計(jì)算 
 if e.widget['text'] == '=': 
  try: 
  res = eval(self.lable_show['text'][:-1]) 
  #print(res) 
  #小數(shù)點(diǎn)取到9位 
  self.lable_show['text'] = str(round(float(res), 5)) 
  self.isinit = True 
  except ZeroDivisionError: 
  #除法時(shí)，除數(shù)不能為0 
  self.mbox.showerror(message='除法計(jì)算時(shí)！除數(shù)不能為0！') 
  except: 
  self.mbox.showerror(message='算式有誤') 
 #取消當(dāng)前輸入的字符 
 if e.widget['text'] == 'C': 
  cancel_res = self.lable_show['text'][:-2] 
  self.lable_show['text'] = cancel_res 
 
 
#實(shí)例化計(jì)算器對(duì)象 
wiz = Counter()