"""
File: breezypythongui.py
Version: 1.0

Resources for easy Python GUIs.

LICENSE: This is open-source software released under the terms of the
GPL (http://www.gnu.org/licenses/gpl.html). Its capabilities mirror those
of BreezyGUI and BreezySwing, open-source frameworks for writing GUIs in Java,
written by Ken Lambert and Martin Osborne.

PLATFORMS: The package is a wrapper around tkinter (Python 3.X) and should
run on any platform where tkinter is available.

INSTALLATION: Put this file where Python can see it.

"""

import tkinter
import tkinter.simpledialog

N = tkinter.N
S = tkinter.S
E = tkinter.E
W = tkinter.W
CENTER = tkinter.CENTER
END = tkinter.END
NORMAL = tkinter.NORMAL
DISABLED = tkinter.DISABLED
NONE = tkinter.NONE
WORD = tkinter.WORD
VERTICAL = tkinter.VERTICAL
HORIZONTAL = tkinter.HORIZONTAL
RAISED = tkinter.RAISED
SINGLE = tkinter.SINGLE
ACTIVE = tkinter.ACTIVE

class EasyFrame(tkinter.Frame):
"""Represents an application window."""

def __init__(self, title = "", width = None, height = None,
            background = "white", resizable = True):
   """Will shrink wrap the window around the widgets if width
   and height are not provided."""
   tkinter.Frame.__init__(self, borderwidth = 4, relief = "sunken")
   if width and height:
         self.setSize(width, height)
   self.master.title(title)
   self.grid()
   # Expand the frame within the window
   self.master.rowconfigure(0, weight = 1)
   self.master.columnconfigure(0, weight = 1)
   self.grid(sticky = N+S+E+W)
   # Set the background color and resizability
   self.setBackground(background)
   self.setResizable(resizable)

def setBackground(self, color):
   """Resets the window's background color to color."""
   self["background"] = color

def setResizable(self, state):
   """Resets the window's resizable property to True
   or False."""
   self.master.resizable(state, state)

def setSize(self, width, height):
   """Resets the window's width and height in pixels."""
   self.master.geometry(str(width)+ "x" + str(height))

def setTitle(self, title):
   """Resets the window's title to title."""
   self.master.title(title)

# Methods to add widgets to the window. The row and column in
# the grid are required arguments.

def addLabel(self, text, row, column,
            columnspan = 1, rowspan = 1,
            sticky = N+W, font = None,
            background = "white", foreground = "black"):
   """Creates and inserts a label at the row and column,
   and returns the label."""
   label = tkinter.Label(self, text = text, font = font,
                           background = background,
                           foreground = foreground)
   self.rowconfigure(row, weight = 1)
   self.columnconfigure(column, weight = 1)
   label.grid(row = row, column = column,
               columnspan = columnspan, rowspan = rowspan,
               padx = 5, pady = 5, sticky = sticky)
   return label

def addButton(self, text, row, column,
               columnspan = 1, rowspan = 1,
               command = lambda: None,
               state = NORMAL):
   """Creates and inserts a button at the row and column,
   and returns the button."""
   button = tkinter.Button(self, text = text,
                           command = command, state = state)
   self.rowconfigure(row, weight = 1)
   self.columnconfigure(column, weight = 1)
   button.grid(row = row, column = column,
               columnspan = columnspan, rowspan = rowspan,
               padx = 5, pady = 5)
   return button

def addFloatField(self, value, row, column,
                  columnspan = 1, rowspan = 1,
                  width = 20, precision = None,
                  sticky = N+E, state = NORMAL):
   """Creates and inserts a float field at the row and column,
   and returns the float field."""
   field = FloatField(self, value, width, precision, state)
   self.rowconfigure(row, weight = 1)
   self.columnconfigure(column, weight = 1)
   field.grid(row = row, column = column,
               columnspan = columnspan, rowspan = rowspan,
               padx = 5, pady = 5, sticky = sticky)
   return field

def addIntegerField(self, value, row, column,
                     columnspan = 1, rowspan = 1,
                     width = 10, sticky = N+E, state = NORMAL):
   """Creates and inserts an integer field at the row and column,
   and returns the integer field."""
   field = IntegerField(self, value, width, state)
   self.rowconfigure(row, weight = 1)
   self.columnconfigure(column, weight = 1)
   field.grid(row = row, column = column,
               columnspan = columnspan, rowspan = rowspan,
               padx = 5, pady = 5, sticky = sticky)
   return field

def addTextField(self, text, row, column,
                  columnspan = 1, rowspan = 1,
                  width = 20, sticky = N+E, state = NORMAL):
   """Creates and inserts a text field at the row and column,
   and returns the text field."""
   field = TextField(self, text, width, state)
   self.rowconfigure(row, weight = 1)
   self.columnconfigure(column, weight = 1)
   field.grid(row = row, column = column,
               columnspan = columnspan, rowspan = rowspan,
               padx = 5, pady = 5, sticky = sticky)
   return field

def addTextArea(self, text, row, column, rowspan = 1, columnspan = 1,
               width = 80, height = 5, wrap = NONE):
   """Creates and inserts a multiline text area at the row and column,
   and returns the text area. Vertical and horizontal scrollbars are
   provided."""
   frame = tkinter.Frame(self)
   frame.grid(row = row, column = column,
               columnspan = columnspan, rowspan = rowspan,
               sticky = N+S+E+W)
   self.columnconfigure(column, weight = 1)
   self.rowconfigure(row, weight = 1)
   xScroll = tkinter.Scrollbar(frame, orient = HORIZONTAL)
   xScroll.grid(row = 1, column = 0, sticky = E+W)
   yScroll = tkinter.Scrollbar(frame, orient = VERTICAL)
   yScroll.grid(row = 0, column = 1, sticky = N+S)
   area = TextArea(frame, text, width, height,
                     xScroll.set, yScroll.set, wrap)
   area.grid(row = 0, column = 0,
               padx = 5, pady = 5, sticky = N+S+E+W)
   frame.columnconfigure(0, weight = 1)
   frame.rowconfigure(0, weight = 1)
   xScroll["command"] = area.xview
   yScroll["command"] = area.yview
   return area

def addListbox(self, row, column, rowspan = 1, columnspan = 1,
               width = 10, height = 5, listItemSelected = lambda index: index):
   """Creates and inserts a scrolling list box at the row and column, with a
   width and height in lines and columns of text, and a default item selection
   method, and returns the list box."""
   frame = tkinter.Frame(self)
   frame.grid(row = row, column = column, columnspan = columnspan, rowspan = rowspan,
               sticky = N+S+E+W)
   self.columnconfigure(column, weight = 1)
   self.rowconfigure(row, weight = 1)
   yScroll = tkinter.Scrollbar(frame, orient = VERTICAL)
   yScroll.grid(row = 0, column = 1, sticky = N+S)
   listBox = EasyListbox(frame, width, height, yScroll.set, listItemSelected)
   listBox.grid(row = 0, column = 0, sticky = N+S+E+W)
   frame.columnconfigure(0, weight = 1)
   frame.rowconfigure(0, weight = 1)
   yScroll["command"] = listBox.yview
   return listBox

def addCanvas(self, canvas = None, row = 0, column = 0,
               rowspan = 1, columnspan = 1, width = 200, height = 100,
               background = "white"):
   """Creates and inserts a canvas at the row and column,
   and returns the canvas."""

In this assignment you are to create a GUI application, basic_calcu...