[Tkinter] how to add two buttons with different functions in Tk

[deanhystad]

You are reusing variable names.
textbox2 is an entry in line 22 and a different entry in line 68. Line 68 executes last, so textbox2 is the second entry. When btn2_click executes, it gets text from the second entry, not the first. I also don't see any code that places the first textbox2.

There can be only one mainloop() in your program. After you make everything you call mainloop(). mainloop() will block the program until the root window is closed.