Tetris Stackoverflow question

import sys, time, random, os, base64
import pygame

BLACK = (0, 0, 0)
WHITE = (255, 255, 255)
RED = (128, 0, 0)
GREEN = (0, 128, 0)
BLUE = (0, 0, 128)
DARK_GRAY = (32, 32, 32)
LOVELY_BLUE = (22, 54, 83)

SPRITE_DATA_FILENAME = "blocks.png"
SPRITE_DATA =   b'iVBORw0KGgoAAAANSUhEUgAAACoAAAAGCAMAAACCc/wkAAAAAXNSR0IArs4c6QAAAGBQTFRFAAA\
                AIiA0RSg8Zjkxj1Y733Em2aBm7sOa+/I2meVQar4wN5RuS2kvUkskMjw5Pz90MGCCW27hY5v/X83k\
                y9v8////m623hH6HaWpqWVZSdkKKrDIy2Vdj13u6j5dKim8w+2O8zwAAACB0Uk5TAP///////////\
                /////////////////////////////+Smq12AAAAPklEQVQYlWMQJRowiDIAAYRGIxmgJEQVhIDwEB\
                KiUA1gBFYFUQYXYhBF0oBQCrMHyQEMokgkQgOSCxiI9xYACEgN8+zH0H8AAAAASUVORK5CYII='

SHAPES = [
    [
        [
            [0, 0, 0, 0], [0, 1, 1, 0], [0, 1, 1, 0], [0, 0, 0, 0] # O
        ]
    ],
    [
        [
            [0, 0, 0, 0], [2, 2, 2, 2], [0, 0, 0, 0], [0, 0, 0, 0] # I
        ],
        [
            [0, 0, 2, 0], [0, 0, 2, 0], [0, 0, 2, 0], [0, 0, 2, 0]
        ]
    ],
    [
        [
            [0, 0, 0, 0], [0, 0, 3, 3], [0, 3, 3, 0], [0, 0, 0, 0] # S
        ],
        [
            [0, 0, 3, 0], [0, 0, 3, 3], [0, 0, 0, 3], [0, 0, 0, 0]
        ]
    ],
    [
        [
            [0, 0, 0, 0], [0, 4, 4, 0], [0, 0, 4, 4], [0, 0, 0, 0] # Z
        ],
        [
            [0, 0, 0, 4], [0, 0, 4, 4], [0, 0, 4, 0], [0, 0, 0, 0]
        ]
    ],
    [
        [
            [0, 0, 0, 0], [0, 5, 5, 5], [0, 5, 0, 0], [0, 0, 0, 0] # L
        ],
        [
            [0, 0, 5, 0], [0, 0, 5, 0], [0, 0, 5, 5], [0, 0, 0, 0]
        ],
        [
            [0, 0, 0, 5], [0, 5, 5, 5], [0, 0, 0, 0], [0, 0, 0, 0]
        ],
        [
            [0, 5, 5, 0], [0, 0, 5, 0], [0, 0, 5, 0], [0, 0, 0, 0]
        ]
    ],
    [
        [
            [0, 0, 0, 0], [0, 6, 6, 6], [0, 0, 0, 6], [0, 0, 0, 0] # J
        ],
        [
            [0, 0, 6, 6], [0, 0, 6, 0], [0, 0, 6, 0], [0, 0, 0, 0]
        ],
        [
            [0, 6, 0, 0], [0, 6, 6, 6], [0, 0, 0, 0], [0, 0, 0, 0]
        ],
        [
            [0, 0, 6, 0], [0, 0, 6, 0], [0, 6, 6, 0], [0, 0, 0, 0]
        ]
    ],
    [
        [
            [0, 0, 0, 0], [0, 7, 7, 7], [0, 0, 7, 0], [0, 0, 0, 0] # T
        ],
        [
            [0, 0, 7, 0], [0, 0, 7, 7], [0, 0, 7, 0], [0, 0, 0, 0]
        ],
        [
            [0, 0, 7, 0], [0, 7, 7, 7], [0, 0, 0, 0], [0, 0, 0, 0]
        ],
        [
            [0, 0, 7, 0], [0, 7, 7, 0], [0, 0, 7, 0], [0, 0, 0, 0]
        ]
    ],
]

# handy way of working with coordinate integers
class vect:
    def __init__(s, x, y = None):
        if type(x) is tuple:
            s.x = int(x[0])
            s.y = int(x[1])
        else:
            s.x = int(x)
            if y == None:
                s.y = s.x
            else:
                s.y = int(y)
        s.v = (s.x, s.y)

    def __add__(s, n):
        if type(n) is tuple:
            return vect(s.x + n[0], s.y + n[1])
        elif type(n) is vect:
            return vect(s.x + n.x, s.y + n.y)
        else:
            return vect(s.x + n, s.y + n)

    def __sub__(s, n):
        if type(n) is tuple:
            return vect(s.x - n[0], s.y - n[1])
        elif type(n) is vect:
            return vect(s.x - n.x, s.y - n.y)
        else:
            return vect(s.x - n, s.y - n)

    def __mul__(s, n):
        if type(n) is tuple:
            return vect(s.x * n[0], s.y * n[1])
        elif type(n) is vect:
            return vect(s.x * n.x, s.y * n.y)
        else:
            return vect(s.x * n, s.y * n)

    def __truediv__(s, n):
        if type(n) is tuple:
            return vect(s.x / n[0], s.y / n[1])
        elif type(n) is vect:
            return vect(s.x / n.x, s.y / n.y)
        else:
            return vect(s.x / n, s.y / n)

    def __str__(s):
        return "({}, {})".format(s.x, s.y)

    def setX(s, x):
        s.x = x
        s.v = (x, s.y)

    def setY(s, y):
        s.y = y
        s.v = (s.x, y)

class spritesheet:
    def __init__(s, surface, cols, rows, colorkey = None):
        # sprite sheet surface
        s.sheet = surface

        # get width and height
        s.sheetSize = vect(surface.get_rect().size)

        # n rows and n columns
        s.grid = vect(cols, rows)

        # list to references the subsurfaces of the spritesheet.
        s.sprites = []

        # size of each individual sprite
        s.cellSize = s.sheetSize / s.grid

        # iterate through spritesheet to define individual subsurfaces
        for y in range(rows):
            for x in range(cols):
                # get position of each sprite
                pos = vect(x, y) * s.cellSize

                # add subsprite to the list
                s.sprites.append(surface.subsurface((pos.v, s.cellSize.v)))

    # return a sprite by id
    def get(s, id):
        return s.sprites[id]


class shape:
    def __init__(s, id):
        global SHAPES

        # shape id
        s.id = id

        # rotation
        s.r = 0

        # maxium number of available shape rotations
        s.maxr = len(SHAPES[id])

        # if the top row of the shape is blank then y = -1
        if sum(SHAPES[id][0][0]):
            s.pos = vect(3, 0)
        else:
            s.pos = vect(3, -1)

    def draw(s, addBlur = False):
        global PAS # play area surface
        global SHAPES

        for y in range(4):
            for x in range(4):
                bid = SHAPES[s.id][s.r][y][x] # block sprite id
                # blit sprite to play area surface if bid > 0
                if bid:
                    if addBlur:
                        PAS.blit(SPRITES.get(7), ((s.pos + vect(x, y - 1)) * SPRITES.cellSize).v)
                    PAS.blit(SPRITES.get(bid - 1), ((s.pos + vect(x, y)) * SPRITES.cellSize).v)

    def collision(s, offset, rOffset = None):
        global PLAY_AREA, PLAY_AREA_SIZE, SHAPES

        # check if collision involves shape rotation
        if rOffset == None:
            # grab a copy of the shape data if using current rotation value
            shapeData = SHAPES[s.id][s.r]
        else:
            # adjust rotation if it has gone out of bounds
            rotation = s.r + rOffset
            if rotation >= s.maxr: rotation = 0
            elif rotation < 0: rotation = s.maxr - 1

            # grab a copy of the shape data using new rotation value
            shapeData = SHAPES[s.id][rotation]

        # iterate throught the shape data to determine:
        # 1. has the shape collided with the wall?
        # 2. has the shape collided with the floor?
        # 3. does the shape rotate out of the ceiling?
        # 3. has the shape collided with the stack?

        for y in range(4):
            for x in range(4):
                # calculate the absolute position of each block within the shape.
                pos = s.pos + vect(x, y) + offset

                # if the shape data is a block ie has a value >0
                if shapeData[y][x]:
                    if pos.x < 0 or pos.x > PLAY_AREA_SIZE.x - 1: return "WALL"
                    if pos.y > PLAY_AREA_SIZE.y - 1: return "FLOOR"
                    if pos.y < 0: return "CEILING"
                    if PLAY_AREA[pos.y][pos.x]: return "STACK"

        # no collision detected
        return "OK"

    # add the shape to play areas data
    def solidify(s):
        global SHAPES, PLAY_AREA
        for y in range(4):

            for x in range(4):
                # get the block id from the shape data
                bid = SHAPES[s.id][s.r][y][x]
                # if the block data >0
                if bid:
                    # get the absolution position of the shape's block in the play area
                    pos = s.pos + (x, y)
                    # copy the block data to the play area
                    PLAY_AREA[pos.y][pos.x] = bid

    # increment the rotation clockwise by one
    def rotate(s):
        s.r += 1
        if s.r >= s.maxr: s.r = 0


# start pygame and create primary display surface (PDS)
pygame.init()
PDR = pygame.Rect(0, 0, 1024, 720)
PDS = pygame.display.set_mode(PDR.size)
FPS = 30

# check if the blocks.png exists. If not then create it
if not os.path.exists(SPRITE_DATA_FILENAME):
    print("Writing title image...", end = "")
    data = base64.b64decode(SPRITE_DATA)
    r = open(SPRITE_DATA_FILENAME, "bw")
    r.write(data)
    r.close()
    print("Done!")

# load the spritesheet
BLOCK_SPRITES = pygame.image.load("blocks.png").convert_alpha()
SPRITES = spritesheet(BLOCK_SPRITES, 8, 1)

# define the scale of the graphics
SCALE = vect(5)

# define the size in blocks of the play area
PLAY_AREA_SIZE = vect(10, 20)

# define the play area data. A 2 dimensional list
PLAY_AREA = [[0] * PLAY_AREA_SIZE.x for y in range(PLAY_AREA_SIZE.y)]

# the size of play area surface in pixels
PLAY_AREA_PIXEL_SIZE = PLAY_AREA_SIZE * SPRITES.cellSize

# scaled size of the play area in pixels
SCALED_PLAY_AREA_PIXEL_SIZE = PLAY_AREA_PIXEL_SIZE * SCALE
SCALED_PLAY_AREA_PLACEMENT = (vect(PDR.size) - SCALED_PLAY_AREA_PIXEL_SIZE) / 2

# create play area surface
PAS = pygame.Surface(PLAY_AREA_PIXEL_SIZE.v)

# define the shape
currentShape = shape(random.randint(0, 6))

# drop down one line timer
TIMER_DURATION = 15
timer = TIMER_DURATION

# prevent the shape spining like a catherine wheel if the up key if held down
rotateKeyDown = False

# add blur lines if the player presses down key
drawDropLines = False

while True:
    events = pygame.event.get()
    for e in events:
        if e.type == pygame.QUIT: sys.exit()

    # clear the play area
    PAS.fill(LOVELY_BLUE)

    # draw the current shape
    currentShape.draw(drawDropLines)

    # translate the play area data into sprites IDs to blit of the play area surface
    for y in range(PLAY_AREA_SIZE.y):
        for x in range(PLAY_AREA_SIZE.x):

            # get data from the play area located at y,x
            id = PLAY_AREA[y][x]

            # if the data in the play area list is >0 then translate to sprite ID and blit
            if id:
                PAS.blit(SPRITES.get(id - 1), (vect(x, y) * SPRITES.cellSize).v)

    # update the display
    PDS.blit(pygame.transform.scale(PAS, SCALED_PLAY_AREA_PIXEL_SIZE.v), SCALED_PLAY_AREA_PLACEMENT.v)
    pygame.display.update()
    pygame.time.Clock().tick(FPS)

    # decrement the drop timer
    timer -= 1

    # if the drop timer reaches zero set the y velocity to 1 (ie drops one line)
    if timer <= 0:
        timer = TIMER_DURATION
        drawDropLines = False
        collisionResults = currentShape.collision((0, 1))
        if collisionResults == "FLOOR" or collisionResults == "STACK":
            # add the shape to the play area's data
            currentShape.solidify()
            currentShape = shape(random.randint(0, 6))

            """ STACKOVER FLOW QUESTION START """
            newPLAY_AREA = []
            fullRowsCount = 0
            for row in reversed(PLAY_AREA):
                rowBlockCount = sum(col > 0 for col in row)
                if rowBlockCount < PLAY_AREA_SIZE.x:
                    newPLAY_AREA = [row] + newPLAY_AREA
                else:
                    fullRowsCount += 1
            if fullRowsCount:
                newPLAY_AREA = [[0] * PLAY_AREA_SIZE.x] * fullRowsCount + newPLAY_AREA
                PLAY_AREA = newPLAY_AREA
                del newPLAY_AREA
            """ STACKOVER FLOW QUESTION END """

            continue

        # move the shape down if no collision with the stack
        currentShape.pos += (0, 1)

    # get key presses and move/rotate the current shape
    k = pygame.key.get_pressed()
    if k[pygame.K_RIGHT]:
        if currentShape.collision((1, 0)) == "OK":
            currentShape.pos += (1, 0)
    elif k[pygame.K_LEFT]:
        if currentShape.collision((-1, 0)) == "OK":
            currentShape.pos += (-1, 0)
    if k[pygame.K_UP] and not rotateKeyDown:
        rotateKeyDown = True
        if currentShape.collision((0, 0), 1) == "OK":
            currentShape.rotate()
    elif not k[pygame.K_UP] and rotateKeyDown:
        rotateKeyDown = False
    if k[pygame.K_DOWN]:
        timer = 0
        drawDropLines = True
    else:
        drawDropLines = False

    if k[pygame.K_SPACE]:
        pass


pygame.quit()
sys.exit()