如何将变量从一个类转移到另一个类？

Question

I'm trying to program a application that carries over user inputs from one page to the other where the pages are separated by classes. A problem I'm having is that the array output on page 2 isn't updating. Basically the output is just [] which is just the starting initialized variable. I've tried some solutions I've found on stack overflow such as calling it a global variable again at the init bit of the PageTwo class as well as trying to use PageOne.overall_data and using self.overall_data but the problem persists although there weren't any errors. This is a part of the code before I tried anything. I tried to cut out the irrelevant bits but I'm not sure if I cut out too much, feedback is much appreciated. Thanks for reading!

import tkinter as tk
import tkinter_nav as tknav
from tkinter import ttk
import numpy as np
class App(tknav.Wrapper):

     def __init__(self):
          tknav.Wrapper.__init__(
            self,
            pages=[PageOne, PageTwo],
            start_state={'previous_page': None}
        )
          self.geometry('450x450')
          self.show_page('page_one')
class PageOne(tknav.Page):

    def __init__(self, parent):
          tknav.Page.__init__(self, parent, 'page_one')
          player_details = []
          global overall_data
          overall_data = []
          my_notebook = ttk.Notebook(self)
          my_notebook.pack(pady = 15)
          my_notebook.pack(fill="both", expand=True)
          my_frame1 = tk.Frame(my_notebook, width = "500", height = "500")
          def submit():                        #called every time inputs are made to be appended to player_details then overall_data
             player_details = []
             global overall_data
             player_details.append(name.get())
             player_details.append(health.get())
             player_details.append(ac.get())
             player_details.append(initiative.get())
             overall_data.append(player_details)
             overall_data = sorted(overall_data, key = lambda x:x[3])
             print(str(overall_data))
class PageTwo(tknav.Page):        #second page of the application

    def __init__(self, parent):
        tknav.Page.__init__(self, parent, 'page_two')

        tk.Label(
            self,
            text='Page Two'
        ).pack()

        tk.Button(
            self,
            text='Navigate to Page One',
            command=lambda: self.__navigate(),
        ).pack()

        line21 = tk.Label(self, text = str(overall_data), font = ('Times New Roman', 12))
        line21.place(x = 30, y  = 30, width = 100, height = 25)
    def __navigate(self):
        print('navigating to page one')
        self.navigate('page_one')


if __name__ == '__main__':
    App().mainloop()

Answer 1

You can put your data at the class level in PageOne like this:

class PageOne(tknav.Page):
    overall_data = []

and use it everywhere like this:

    PageOne.overall_data.append(player_details)

Answer 2

Since you have used tkinter_nav , you can use its provided app_state to share data between pages:

class App(tknav.Wrapper):
     def __init__(self):
        tknav.Wrapper.__init__(
            self,
            pages=[PageOne, PageTwo],
            start_state={'previous_page': None, 'overall_data': []} # added 'overall_data'
        )
        self.geometry('450x450')
        self.show_page('page_one')

Then you can access this shared data in each page by:

self.app_state['overall_data']