kivy - self not defined

I am trying to run this Python program from a Python book that I've picked up named "Python The Complete Manual", however the instructions read for Python 2.7 and I am running Python 3.5.

This program runs in the kivy environment, as I am using it to create an app. The issue that I'm currently having is that when I run the program, I get an error message that says 'self' is not defined. I've already tried changing the syntax, moving the functions(because I thought that it would have to read the functions in a specified order), and even removed the whole line completely. I still get the same self not defined error no matter how I try.

Here is the code along with the error message:

#!/usr/bin/env python

import kivy
from kivy.core.window import Window
from kivy.app import App
from kivy.uix.label import Label
from kivy.uix.gridlayout import GridLayout
from kivy.uix.button import Button
from kivy.properties import ListProperty


class GridEntry(Button):
    coords = ListProperty([0, 0])


class TicTacToeApp(App):
    pass

    def build(self):
        return TicTacToeGrid()


class TicTacToeGrid(GridLayout):

    def __init__(self, *args, **kwargs):
        super(TicTacToeGrid, self).__init__(*args, **kwargs)

    def button_pressed(self, instance):
        print('{} button clicked!'.format(instance.coords))


    for row in range(3):
        for column in range(3):
            grid_entry = GridEntry(coords=(row, column))
            grid_entry.bind(on_release=self.button_pressed)
            self.add_widget(grid_entry)


if __name__ == "__main__":
    TicTacToeApp().run()

Output:

    (kivy_venv) root@c0mputer:/home/chavez/Documents/Python# ./ticTacToe.py 
    [INFO   ] [Logger      ] Record log in /root/.kivy/logs/kivy_20-01-06_1.txt
    [INFO   ] [Kivy        ] v1.11.1
    [INFO   ] [Kivy        ] Installed at "/home/chavez/Documents/Python/kivy_venv/lib/python3.5/site-packages/kivy/__init__.py"
    [INFO   ] [Python      ] v3.5.2 (default, Oct  8 2019, 13:06:37) 
    [GCC 5.4.0 20160609]
    [INFO   ] [Python      ] Interpreter at "/home/chavez/Documents/Python/kivy_venv/bin/python"
    [INFO   ] [Logger      ] Purge log fired. Analysing...
    [INFO   ] [Logger      ] Purge finished!
    [INFO   ] [Factory     ] 184 symbols loaded
    [INFO   ] [Image       ] Providers: img_tex, img_dds, img_sdl2, img_gif (img_pil, img_ffpyplayer ignored)
    [INFO   ] [Window      ] Provider: sdl2(['window_egl_rpi'] ignored)
    [INFO   ] [GL          ] Using the "OpenGL" graphics system
    [INFO   ] [GL          ] Backend used <sdl2>
    [INFO   ] [GL          ] OpenGL version <b'3.0 Mesa 18.0.5'>
    [INFO   ] [GL          ] OpenGL vendor <b'Intel Open Source Technology Center'>
    [INFO   ] [GL          ] OpenGL renderer <b'Mesa DRI Intel(R) HD Graphics 520 (Skylake GT2) '>
    [INFO   ] [GL          ] OpenGL parsed version: 3, 0
    [INFO   ] [GL          ] Shading version <b'1.30'>
    [INFO   ] [GL          ] Texture max size <16384>
    [INFO   ] [GL          ] Texture max units <32>
    [INFO   ] [Window      ] auto add sdl2 input provider
    [INFO   ] [Window      ] virtual keyboard not allowed, single mode, not docked
    [INFO   ] [Text        ] Provider: sdl2
     Traceback (most recent call last):
       File "./ticTacToe.py", line 23, in <module>
         class TicTacToeGrid(GridLayout):
       File "./ticTacToe.py", line 35, in TicTacToeGrid
         grid_entry.bind(on_release=self.button_pressed)
     NameError: name 'self' is not defined

I am new to this forum(only having viewed questions and answers and not actually signing up to the site). Thank you @Error -Syntactical Remorse, that was the correct answer I was looking for. Be it simple but I am fairly new to Python and haven't even heard of kivy until I started reading this book. Also, another thing that I do not like about getting the right answer is that the person that posts the question and gets the right answer almost never posts his/her/their code the way it was answered correctly. I just usually see, "Oh! that solved it!"... so, I will post where the correction is here:

#!/usr/bin/env python

import kivy
from kivy.core.window import Window
from kivy.app import App
from kivy.uix.label import Label
from kivy.uix.gridlayout import GridLayout
from kivy.uix.button import Button
from kivy.properties import ListProperty


class GridEntry(Button):
    coords = ListProperty([0, 0])


class TicTacToeApp(App):
    def build(self):
        return TicTacToeGrid()


class TicTacToeGrid(GridLayout):

    def __init__(self, *args, **kwargs):
        super(TicTacToeGrid, self).__init__(*args, **kwargs)
        for row in range(3):
            for column in range(3):
                grid_entry = GridEntry(coords=(row, column))
                grid_entry.bind(on_release=self.button_pressed)
                self.add_widget(grid_entry)

    def button_pressed(self, instance):
        print('{} button clicked!'.format(instance.coords))

if __name__ == "__main__":
    TicTacToeApp().run()