change text on tkinter text widget code example
Example 1: text widget get tkinter
contents = text.get(1.0, END)
Example 2: how to change text of Button in tkinter
from tkinter import *
import tkinter.font as font
gui = Tk(className='Python Examples - Button')
gui.geometry("500x200")
# define font
myFont = font.Font(size=30)
# create button
button = Button(gui, text='My Button', bg='#0052cc', fg='#ffffff')
# apply font to the button label
button['font'] = myFont
# add button to gui window
button.pack()
gui.mainloop()