python Tkinter学习笔记 简单的计算器 03

'''Created on 2013-9-27@author: liangqianwu'''#_*_ coding:utf-8_*_from Tkinter import * def frame(root,side):    w=Frame(root)    w.pack(side=side,expand=YES,fill=BOTH)    return wdef button(root,side,text,command=None):    w=Button(root,text=text,command=command)    w.pack(side=side,expand=YES,fill=BOTH)    return wclass Calculator(Frame):    def __init__(self):        Frame.__init__(self)        self.pack(expand=YES,fill=BOTH)        self.master.title('hello Calculator')        self.master.iconname('calcl')        display=StringVar()        Entry(self,relief=SUNKEN,textvariable=display).pack(side=TOP,expand=YES,fill=BOTH)        for key in('123','456','789','-0+'):            keyF=frame(self,TOP)            for char in key:                button(keyF,LEFT,char,lambda w=display,s='%s'%char:w.set(w.get()+s))        opsF=frame(self,TOP)        for char in '+-*/=':            if char == '=':                btn=button(opsF,LEFT,char)                btn.bind('<ButtonRelease-1>',lambda e,s=self,w=display:s.calc(w),'+')            else:                btn=button(opsF,LEFT,char,lambda w=display,c=char:w.set(w.get()+''+c+''))        clearF=frame(self,BOTTOM)        button(clearF,LEFT,'Clr',lambda w=display:w.set(''))    def calc(self,display):        try:            display.set(`eval(display.get())`)        except ValueError:            display.set('ERROR')if __name__ =='__main__':    Calculator().mainloop()