ΘΕΜΑ: calculator

$ python3 calcula
tor.py
Traceback (most recent call last):
  File "calculator.py", line 113, in <module>
    calc = Calculator(master = root)
  File "calculator.py", line 111, in __init__
    self.drawGUI()
  File "calculator.py", line 83, in drawGUI
    self.insertNum()
AttributeError: 'Calculator' object has no attribute 'insertNum'

from tkinter import *
from tkinter.messagebox import *
class Calculator(Frame):
    """ Describes the main behaviour o f a c a l c u l a t o r
    """
    def d_result(self, c):
    	""" Displays the r e s u l t o f an operation
    	"""
    	self.label3.config(text = 'The result is ' + str(c))
    	self.label3.pack()
    def d_add(self):
    	""" Handles the addition in the GUI
    	"""
    	a, b = self.getNum()
    	c = self.addition(a, b)
    	self.d_result(c)
    def d_sub(self):
    	""" Handles the substraction in the GUI
    	"""
    	a, b = self.getNum()
    	c = self.substraction(a, b)
    	self.d_result(c)
    def d_mul(self):
    	""" Handles the m u l t i p l i c a t i o n in the GUI
    	"""
    	a, b = self.getNum()
    	c = self.multiplication(a, b)
    	self.d_result(c)
    def d_div(self):
    	""" Handles the d i v i s i o n in the GUI
    	"""
    	a, b = self.getNum()
    	c = self.division(a, b)
    	self.d_result(c)
    def addition(self, a, b):
    	""" Add numbers a , b and return t h e i r r e s u l t
    	"""
    	c = a + b
    	return c
    def substraction(self, a, b):
    	""" Substract a − b and return the r e s u l t
    	"""
    	c = a - b
    	return c
    def multiplication(self, a, b):
    	""" Multiply a ∗ b and return i t s r e s u l t
    	"""
    	c = a * b
    	return c
    def division(self, a, b):
    	""" Divide a / b and return i t s r e s u l t
    	"""
    	try:
    		if b != 0:
    			c = a/b
    	except ZeroDivisionError:
    		if b == 0:
    			showinfo('Warning ', ' Cannot divide by 0.')
    		c = 0
    		return c
    def getNum(self):
    	""" Gets the two numbers on which the operation
    	w i l l be applied.
    	In case o f error , i t returns both o f them as zero
    	and warns the user.
    	"""
    	try:
    		a = float(self.enter1.get())
    		b = float(self.enter2.get())
    		#if the f i e l d s were empty
 
    	except ValueError :
    		a, b = 0, 0
    		showinfo('Info', 'There are some empty fields')
    		return a, b
    def drawGUI(self):
    	"""
    	I t draws the GUI within the container from which i s
    	c a l l e d . In t h i s case , within the frame where the
    	c a l c u l a t o r belongs.
    	"""
    	# draws the elements which are used t o i n s e r t a number
    	self.insertNum()
    	# set the focus t o enter1
    	self.enter1.focus()
    	# create the  buttons
    	self.button1 = \
    	Button(self, text = "add", command = self.d_add)
    	self.button2 = \
    	Button(self, text = "sub", command = self.d_sub)
    	self.button3 = \
    	Button(self, text = "mul", command = self.d_mul)
    	self.button4 = \
    	Button(self, text = "div", command = self.d_div)
    	# display them
    	self.button1.pack(side=LEFT)
    	self.button2.pack(side=LEFT)
    	self.button3.pack(side=LEFT)
    	self.button4.pack(side=LEFT)
    	# create the l a b e l where we display the r e s u l t
    	self.label3 = Label(self)
    	return root;
    def __init__(self, master = None):
          """
          The constructor i s c a l l e d with a parent widget .
          I t creates the GUI f o r the c a l c u l a t o r .
          """
          Frame.__init__(self, master)
          self.master.title("Calculator")
          self.pack()
          self.drawGUI()
root = Tk()
calc = Calculator(master = root)
calc.mainloop()