example of saving text from one tab onto another in tkinter

save_from_page_to_page.py

import tkinter as tk
from tkinter import ttk


def submit(source, dest):
    """Collect data from source text and insert into destination text"""
    text = source.get('1.0', 'end')
    dest.insert('end', text)


root = tk.Tk()
nb = ttk.Notebook(root)
nb.pack(fill='both', expand='yes')

# page 1 setup
page1 = ttk.Frame(nb)
text1 = tk.Text(page1)
text1.pack(fill='both', expand='yes')
b1 = ttk.Button(page1, text='Submit to Page 2')
b1.pack(fill='x')
nb.add(page1, text='Page 1')


# page 2 setup
page2 = ttk.Frame(nb)
text2 = tk.Text(page2)
text2.pack(fill='both', expand='yes')
nb.add(page2, text='Page 2')

# configure button callback
b1.configure(command=lambda x=text1, y=text2: submit(x, y))

root.mainloop()