Python Calculator

Here is a simple code for Calculator in python

 
import simplegui
a=0
b=0
c=0
def input1(str1):
   global a
   a=int(str1)

def input2(str2):
    global b
    b=int(str2)

def add():
    global c
    c=a+b
    print c

def sub():
    global c
    c=a-b
    print c

def mul():
    global c
    c=a*b
    print c

def div():
    global c
    c=a/b
    print c




frame=simplegui.create_frame("Calculator",640,480,340)
txt1=frame.add_input("Enter",input1,200)
txt2=frame.add_input("Enter",input2,200)
button1=frame.add_button("Add",add)
button2=frame.add_button("Sub",sub)
button3=frame.add_button("Mul",mul)
button4=frame.add_button("Div",div)
frame.start()