Menu Example

from tkinter import *

class MenuDemo:
    def __init__(self):
        window = Tk()
        window.title("Menu Demo")


        #Create a menu bar
        menubar = Menu(window)
        window.config(menu = menubar)  # Display the menu bar


        # Create a pull down menu, and add it to the menu bar
        operationMenu = Menu(menubar, tearoff = 0)
        menubar.add_cascade(label = "Operation", menu = operationMenu)
        operationMenu.add_command(label = "Add", command = self.add)
        operationMenu.add_command(label = "Subtract", command = self.subtract)
        operationMenu.add_separator()
        operationMenu.add_command(label = "Multiply", command = self.multiply)
        operationMenu.add_command(label = "Divide", command = self.divide)

        # Create more pull-down menus
        exitmenu = Menu(menubar, tearoff = 0)
        menubar.add_cascade(label = "Exit", menu = exitmenu)
        exitmenu.add_command(label = "Quit", command = window.quit)

        # Add a tool bar frame
        frame0 = Frame(window)  # Create and add a frame to window
        frame0.grid(row = 1, column = 1, sticky = W)

        Button(frame0, text="Plus", command = self.add).grid(row = 1, column = 1, sticky = W)
        Button(frame0, text="Minus", command=self.subtract).grid(row=1, column=2)
        Button(frame0, text="Multiply", command=self.multiply).grid(row=1, column=3)
        Button(frame0, text="Divide", command=self.divide).grid(row=1, column=4)


        # Add label and entries to frame1

        frame1 = Frame(window)
        frame1.grid(row = 2, column = 1, pady = 10)
        Label(frame1, text = "Number 1:").pack(side = LEFT)
        self.v1 = StringVar()
        Entry(frame1, width = 5, textvariable = self.v1, justify = RIGHT).pack(side = LEFT)
        Label(frame1, text = "Number 2:").pack(side = LEFT)
        self.v2 = StringVar()
        Entry(frame1, width = 5, textvariable = self.v2, justify = RIGHT).pack(side = LEFT)
        Label(frame1, text = "Result:").pack(side = LEFT)
        self.v3 = StringVar()
        Entry(frame1, width = 5, textvariable = self.v3, justify = RIGHT).pack(side = LEFT)


        # Add buttons to frame2
        frame2 = Frame(window)  # Create and add a frame to window
        frame2.grid(row = 3, column = 1, pady = 10, sticky = E)
        Button(frame2, text = "Add", command = self.add).pack(side = LEFT)
        Button(frame2, text = "Subtract", command = self.subtract).pack(side = LEFT)
        Button(frame2, text= "Multiply", command = self.multiply).pack(side = LEFT)
        Button(frame2, text = "Divide", command = self.divide).pack(side = LEFT)

        window.mainloop()


    def add(self):
        self.v3.set(eval(self.v1.get()) + eval(self.v2.get()))

    def subtract(self):
        self.v3.set(eval(self.v1.get()) - eval(self.v2.get()))

    def multiply(self):
        self.v3.set(eval(self.v1.get()) * eval(self.v2.get()))

    def divide(self):
        self.v3.set(eval(self.v1.get()) / eval(self.v2.get()))

MenuDemo() # Create GUI