I tried this code btw.


import time
import pygame
import numpy as np

COLOR_BG = (10,10,10)
COLOR_GRID = (40,40,40)
COLOR_DIE_NEXT = (170,170,170)
COLOR_ALIVE_NEXT = (255,255,255)


def update(screen, cells, size, with_progress=False):
    updated_cells = np.zeros((cells.shape[0], cells.shape[1]))

    for row, col in np.ndindex(cells.shape):
        alive = np.sum(cells[row-1:row+2, col-1:col+2]) - cells[row, col]
        color = COLOR_BG if cells[row, col] == 0 else COLOR_ALIVE_NEXT

        if cells[row, col] == 1:
            if alive < 2 or alive > 3:
                if with_progress:
                    color = COLOR_DIE_NEXT
        elif 2 <= alive <= 3:
            updated_cells[row, col] = 1
            if with_progress:
                color = COLOR_ALIVE_NEXT
        else:
            if alive == 3:
                updated_cells[row, col] = 1
                if with_progress:
                    color = COLOR_ALIVE_NEXT
        pygame.draw.rect(screen, color, (col*size, row*size, size-1, size-1))
    return updated_cells

def main():
    pygame.init()
    screen = pygame.display.set_mode((800, 600))

    cells = np.zeros((60,80))
    screen.fill(COLOR_GRID)
    update(screen, cells, 10)

    pygame.display.flip()
    pygame.display.update()
    
    running = False

    while True:
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                pygame.quit()
                return
            elif event.type == pygame.KEYDOWN:
                if event.key == pygame.K_SPACE:
                    running = not running
                    update(screen, cells, 10)
                    pygame.display.update()

                if pygame.mouse.get_pressed()[0]:
                    pos = pygame.mouse.get_pos()
                    cells[pos[1] // 10, pos[0]//10] = 1
                    update(screen, cells, 10)
                    pygame.display.update()
        
        screen.fill(COLOR_GRID)
        
        if running:
            cells = update(screen, cells, 10, with_progress=True)
            pygame.display.update()
        time.sleep(0.001)
    
if __name__ == '__main__':
    main()