input_field.py

# calculator with all buttons
import simplegui

# intialize globals
store = 0
operand = 0

# event handlers for calculator with a store and operand

def output():
    """ prints contents of store and operand"""
    print "Store =", store
    print "Operand =", operand
    print ""

def swap():
    """swap contens of store and operand"""
    global store, operand
    store, operand = operand, store
    output()

def add():
    """add operand to store"""
    global store
    store = store + operand
    output()

def sub():
    """subtract operand from store"""
    global store
    store = store - operand
    output()

def mult():
    """multiply operand from store"""
    global store
    store = store * operand
    output()

def div():
    """divide store by operand"""
    global store
    store = store / operand
    output()

def enter(input):
    global operand
    operand = float(input)
    output()

# create frame
f = simplegui.create_frame("Calculator", 300, 300)

# register event handlers
f.add_button("Print", output, 100)
f.add_button("Add", add, 100)
f.add_button("Sub", sub, 100)
f.add_button("Mult", mult, 100)
f.add_button("Div", div, 100)
f.add_input("Enter operand", enter, 100)

# get frame rolling
f.start()