AttributeError: 'NoneType' object has no attribute 'push'

Question

I was watching a lecture on YouTube and making Tetris.

But I got this error.

Traceback (most recent call last):
File "C:\Users\gkakc\PycharmProjects\Tetris\main.py", line 90, in <module>
draw_grid(pen, grid)
File "C:\Users\gkakc\PycharmProjects\Tetris\main.py", line 80, in draw_grid
pen.stamp()
File "C:\Users\gkakc\AppData\Local\Programs\Python\Python39\lib\turtle.py", line 3077, in stamp
self.undobuffer.push(("stamp", stitem))
AttributeError: 'NoneType' object has no attribute 'push'

Process finished with exit code 1

That's the code

import turtle
import time

# wn = Window
wn = turtle.Screen()
wn.title("Tetris by LeeSooHyung")
wn.bgcolor("black")
wn.setup(width=600, height=800)
wn.tracer(0)

delay = 0.05

class Shape():
    def __init__(self):
        self.x = 5
        self.y = 0
        self.color = 4

    def move_left(self, grid):
        if self.x > 0:
            grid[self.y][self.x] = 0
            self.x -= 1
    def move_right(self, grid):
        if self.x < 11:
            grid[self.y][self.x] = 0
            self.x += 1

grid = [
    [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
    [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
    [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
    [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
    [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
    [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
    [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
    [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
    [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
    [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
    [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
    [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
    [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
    [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
    [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
    [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
    [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
    [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
    [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
    [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
    [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
    [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
    [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
    [0, 1, 2, 3, 4, 0, 0, 7, 1, 2, 3, 4]

]
pen = turtle.Turtle()
pen.penup()
pen.speed(0)
pen.shape("square")
pen.setundobuffer(None)

def draw_grid(pen, grid):
    top = 230
    left = -110

    colors = ["black", "lightblue", "blue", "orange", "yellow", "green", "purple", "red"]

    for y in range(len(grid)):
        for x in range(len(grid[0])):
            screen_x = left + (x * 20)
            screen_y = top - (y * 20)
            color_number = grid[y][x]
            color = colors[color_number]
            pen.color(color)
            pen.goto(screen_x, screen_y)
            pen.stamp()


# Create the basic shape for the start of the game
shape = Shape()

# Put the shape in the grid
grid[shape.y][shape.x] = shape.color

# Draw the intial grid
draw_grid(pen, grid)

wn.listen()
wn.onkeypress(shape.move_left(grid), "a")
wn.onkeypress(shape.move_right(grid), "d")

# Main game loop
while True:
    wn.update()

    # Shape move down
    # Open row
    if shape.y == 23: # if shape is in the bottom row
        shape = Shape()

    elif grid[shape.y + 1][shape.x] == 0: # if Nothing there
        grid[shape.y][shape.x] = 0 # Delete the shape of the previous position
        shape.y += 1
        grid[shape.y][shape.x] = shape.color
    else:
        shape = Shape()

    draw_grid(pen, grid)
    time.sleep(delay)

# We have to keep the window open, so I loop it.
wn.mainloop()

I've implemented a block drop.

But it doesn't work after that.

I need your help.

I hope you understood my poor English.

sarath ravi · Answer 1 · 2021-09-05T06:15:21.053

try to append any value for setundobuffer if the value of size in setundobuffer is none then the value of self.undobuffer also none thats why showing this error

def setundobuffer(self, size):
    """Set or disable undobuffer.
    Argument:
    size -- an integer or None
    If size is an integer an empty undobuffer of given size is installed.
    Size gives the maximum number of turtle-actions that can be undone
    by the undo() function.
    If size is None, no undobuffer is present.
    Example (for a Turtle instance named turtle):
    >>> turtle.setundobuffer(42)
    """
    if size is None:
        self.undobuffer = None
    else:
        self.undobuffer = Tbuffer(size)

i don’t know what’s your purpose. I only adding answer for why this error is coming

AttributeError: 'NoneType' object has no attribute 'push'

1 Answers1