Python寫計算器

    # -- coding: utf-8 --


#author: Cullen  
#import the module  

from Tkinter import *  
from functools import partial  
import tkFont  

def get_input(entry, argu):  
    entry.insert(END, argu)  

def backspace(entry):  
    input_len = len(entry.get())  
    entry.delete(input_len - 1)  

def clear(entry):  
    entry.delete(0, END)  

def calc(entry):  
    input = entry.get()  
    output = str(eval(input.strip()))  
    clear(entry)  
    entry.insert(END, output)  

def cal():  
    root = Tk()  
    root.title("Calc")  
    root.resizable(0,0)  

    entry_font = tkFont.Font(size=12)  
    entry = Entry(root, justify="right", font=entry_font)  
    entry.grid(row=0, column=0, columnspan=4, sticky=N+W+S+E, padx=5,  pady=5)  

    button_font = tkFont.Font(size=10, weight=tkFont.BOLD)  
    button_bg = '#D5E0EE'  
    button_active_bg = '#E5E35B'  

    myButton = partial(Button, root, bg=button_bg, padx=10, pady=3, activebackground = button_active_bg)  

    button7 = myButton(text='7', command=lambda : get_input(entry, '7'))  
    button7.grid(row=1, column=0, pady=5)  

    button8 = myButton(text='8', command=lambda : get_input(entry, '8'))  
    button8.grid(row=1, column=1, pady=5)  

    button9 = myButton(text='9', command=lambda : get_input(entry, '9'))  
    button9.grid(row=1, column=2, pady=5)  

    button10 = myButton(text='+', command=lambda : get_input(entry, '+'))  
    button10.grid(row=1, column=3, pady=5)  

    button4 = myButton(text='4', command=lambda : get_input(entry, '4'))  
    button4.grid(row=2, column=0, pady=5)  

    button5 = myButton(text='5', command=lambda : get_input(entry, '5'))  
    button5.grid(row=2, column=1, pady=5)  

    button6 = myButton(text='6', command=lambda : get_input(entry, '6'))  
    button6.grid(row=2, column=2, pady=5)  

    button11 = myButton(text='-', command=lambda : get_input(entry, '-'))  
    button11.grid(row=2, column=3, pady=5)  

    button1 = myButton(text='1', command=lambda : get_input(entry, '1'))  
    button1.grid(row=3, column=0, pady=5)  

    button2 = myButton(text='2', command=lambda : get_input(entry, '2'))  
    button2.grid(row=3, column=1, pady=5)  

    button3 = myButton(text='3', command=lambda : get_input(entry, '3'))  
    button3.grid(row=3, column=2, pady=5)  

    button12 = myButton(text='*', command=lambda : get_input(entry, '*'))  
    button12.grid(row=3, column=3, pady=5)  

    button0 = myButton(text='0', command=lambda : get_input(entry, '0'))  
    button0.grid(row=4, column=0, columnspan=2, padx=3, pady=5, sticky=N+S+E+W)  

    button13 = myButton(text='.', command=lambda : get_input(entry, '.'))  
    button13.grid(row=4, column=2, pady=5)  

    button14 = Button(root, text='/', bg=button_bg, padx=10, pady=3,  
                      command=lambda : get_input(entry, '/'))  
    button14.grid(row=4, column=3, pady=5)  

    button15 = Button(root, text='<-', bg=button_bg, padx=10, pady=3,  
                      command=lambda : backspace(entry), activebackground = button_active_bg)  
    button15.grid(row=5, column=0, pady=5)  

    button16 = Button(root, text='C', bg=button_bg, padx=10, pady=3,  
                      command=lambda : clear(entry), activebackground = button_active_bg)  
    button16.grid(row=5, column=1, pady=5)  

    button17 = Button(root, text='=', bg=button_bg, padx=10, pady=3,  
                      command=lambda : calc(entry), activebackground = button_active_bg)  
    button17.grid(row=5, column=2, columnspan=2, padx=3, pady=5, sticky=N+S+E+W)  

    root.mainloop()  

if __name__ == '__main__':  
    cal()  </pre>