Why there is a problem while displaying image in GUI called from another GUI in python tkinter???

Question

First a wrote a module which has a function that just reads and display the image in GUI. The I wrote another module which imports the first module and makes call to that function when the button is clicked. But it gives me error.

Code :
#button GUI
from tkinter import *
import testimg as ti

def click():
ti.disp()

root = Tk()

Button(text = 'Click me',command=click).pack()
root.mainloop()

#module
from tkinter import *
def disp():
root1 = Tk()
root1.geometry("400x500")
image = PhotoImage(file = 'png2.png')
Label(root1,image=image).pack()
root1.mainloop()

Answer 1

You can have only a single root window in a tkinter application. The root window is created when you call Tk()
https://effbot.org/tkinterbook/tkinter-application-windows.htm