Variables & Setup

The Step 1 program is almost complete. The ? boxes are where you type. Click each one and fill in the correct value, then click Submit Tier 1.

import pygame
pygame.init()

# Grid constants
GRID_COLS  =         # 20 columns
GRID_ROWS  =         # 15 rows
CELL_SIZE  =         # 30x30 pixels per cell
SNAKE_SPEED = 8

# Colour constants - RGB tuples
WHITE   = 
GREEN   = (  0, 200,  80)
DKGREEN = (  0, 160,  50)
RED     = 
BG      = ( 30,  30,  30)

# Calculate window size in pixels
WINDOW_W =  * CELL_SIZE
WINDOW_H = GRID_ROWS * 

screen = pygame.display.set_mode((WINDOW_W, WINDOW_H))
pygame.display.set_caption("Snake")

screen.fill(BG)
pygame.display.flip()
pygame.time.wait(3000)
pygame.quit()

The code below has 3 deliberate bugs. Each will cause a crash or wrong behaviour. For each bug: identify the variable name, explain what is wrong, and write the corrected line.

import pygame
pygame.init()

GRID_COLS   = 20
GRID_ROWS   = 15
CELL_SIZE   = "30"          # ⚠ Bug 1 near here
SNAKE_SPEED = 8

WHITE   = (255, 255, 255)
GREEN   = [0, 200, 80]      # ⚠ Bug 2 near here
DKGREEN = (  0, 160,  50)
RED     = (220,  50,  50)
BG      = ( 30,  30,  30)

WINDOW_W = GRID_COLS + CELL_SIZE   # ⚠ Bug 3 near here
WINDOW_H = GRID_ROWS * CELL_SIZE

screen = pygame.display.set_mode((WINDOW_W, WINDOW_H))
pygame.display.set_caption("Snake")
screen.fill(BG)
pygame.display.flip()
pygame.time.wait(3000)
pygame.quit()

The skeleton below is ~50% complete. Write every missing line to make a working Step 1 program. No bugs here — this is a writing task.

# skeleton — gaps marked with ___
import pygame
pygame.init()

# Write all four grid constants:
GRID_COLS  = ___
GRID_ROWS  = ___
CELL_SIZE  = ___
SNAKE_SPEED = ___

# Write the five colour constants as RGB tuples:
WHITE   = ___
GREEN   = ___
DKGREEN = ___
RED     = ___
BG      = ___

# Calculate window dimensions from the constants:
WINDOW_W = ___
WINDOW_H = ___

# These lines are given:
screen = pygame.display.set_mode((WINDOW_W, WINDOW_H))
pygame.display.set_caption("Snake")

# Write three display lines: fill, flip, wait
___
___
___
pygame.quit()

Answer each prompt thoughtfully. There are no right or wrong answers — this is your own reflection.