Unable to return value from callback function of a button in Python Tkinter

[Windspar]

You never going to be able to print anything in the main area.
Program must run first. Then when program ends. All widgets are destroyed. All this happens when mainloop is called.

Example

import Tkinter as tk

class Main:
    root = tk.Tk()
    value = "None"

class Menu:
    def __init__(self, master):
        self.master = master
        self.entry = tk.Entry(self.master)
        self.entry.pack(side=tk.TOP)
        self.button = tk.Button(master,text='Hit Me',command = self.get_value)
        self.button.pack(side=tk.TOP)
        self.button_send = tk.Button(master, text="Get Text", command=self.get_text)
        self.button_send.pack()
        self.label = tk.Label(master, text=Main.value)
        self.label.pack()

    def get_value(self):
        Main.value = self.entry.get()

    def get_text(self):
        #self.label['text'] = self.entry.get()
        self.label['text'] = Main.value


if __name__=="__main__":
    Main.menu = Menu(Main.root)
    Main.root.mainloop()