#stringvar_example.py
from tkinter import *


class StringVarDemo:
  def __init__(self, rootWin):

      #A StringVar is a special object that holds strings and
      #can be linked to a GUI element such as an Entry.
      self.sv = StringVar()
      
      #Create a entry and button to put in the root window!
      self.entry = Entry(rootWin, textvariable=self.sv)
      self.entry.pack()
      #Add some text:
      self.sv.set("Here is some text!")
      

      self.button = Button(rootWin, text="Click Me!", command=self.clicked)
      self.button.pack()

  def clicked(self):
     print("Button was clicked!")
     eText = self.sv.get()
     print("The Entry had the following text in it:", eText)

     self.sv.set("You clicked!")
     
     



#Create the main root window, instantiate the object, and run the main loop!
rootWin = Tk()
app = StringVarDemo( rootWin )
rootWin.mainloop()