Python Pygame Mario Running Demo

import pygame
from pygame import Rect
from pygame import Vector2
import base64
import os.path
import time

MARIO_SPRITESHEET = b'iVBORw0KGgoAAAANSUhEUgAAAGAAAABACAMAAADS6oI8AAAAAXNSR0IArs4c6QAAAGBQTFRFAAAAIiA0RSg8Zjkxj\
1Y733Em2aBm7sOa+/I2meVQar4wN5RuS2kvUkskMjw5Pz90MGCCW27hY5v/X83ky9v8////m623hH6HaWpqWVZSdkKKrDIy2Vdj13u6j5dKim8w\
+2O8zwAAACB0Uk5TAP////////////////////////////////////////+Smq12AAAEbUlEQVRYhY1XQZIkIQj05Ikf8P9/bgskJGj3TsXEdGl\
hJiAorGWPnmf9/XnL773zY/vsE/vPgF/k9xZj2DsoRJp8W9AQB+BDPmZEbLIIhBYwZEecgJe8QsJ8FOBG52vkvMmeCHt/AZzy+CjnWWYJ/kwmRh\
jeiAPwkidx88mWm8Dec0VHnICXfIqbBT5/huqbLljQEAhxAF7ypG4I+vvZB4kFwR6b3hEn4CXfxGHI+W87HQZihVvcECfgLc/isiQEPj8IymsHJ\
mIHXHMHSNz2OIcZ9iGyOmEziRSAFfUOjeVgHFx1k8oEC2FNhjUQZ+J6QJ7VbINBGiGSDgQCAklCk0g6tQ0jC32sfLoFiBPAB5mYIJAyqOyJrzkh\
4V9R8SDIYeDDaZv0yX8PjyWBEL6bUJsrGi5IAtl1EGhCSHlM4HcQ6E0gie8m1GfxM5sciv+2A2QnCARhBrxQ2bMGm0L82gjqOPQtvgkq7GPFVo9\
Kjx4/ofk7HZUfX6qvcB8pm3CGIJgKaaaVLSeX023jx1LdGBl1RKAg0ACcBHy409Xwi8BklNLKxS7Aj1tqeMZEEBydIHVIjZJPk6C+2/mvbQwP5+\
nDAoOAiwLB2bWpaMg9qwlbgMPjuvO1baLQpS7kVZVOIJNgVRYkfv4mgf1AhPEtp9jRKjIIqvYSqoA6gZQKYECegb2SOCiKYIWH5SuBD0EQcJk3q\
pS0ki5oBBVHQktrtEja30sqLxLKqzUeitNJwKAkTCsH0At/Nf1Jt651P6G/EFzYXcFJcKswbegM3/C72NOLPx6W33xbNwGC3PqbYn4leTQFrHrA\
0/zuDBfbVIDkNy6vqrKSoJvDVk+DmgJdnk/XkLVLrgNGtSsvvJcCJF+pVoRZDufxmBX9E28o0OXpfpsE3k+tqspwvA6DhgJD/hjAC6xe2Sjhd1H\
6ArnwLgWGPIo4LPj8CCrHYPCMQm15GTQVGPIyFtj+opYhgpCRG28ATnlpCzwqpOrtsQsvvDXHT3kSUK0JhAk3CBfeAMxgx+EHZ0DjbA6qIu/Vbu\
JVoi26Y7dj5Lh3B/bRRlq119UfROXAJ6uXov5paRWyWZ1TYsJ+ugR7fwCbuEVIG89SFS4D7EOrCxABPiFM8PTZkk6QBuCwQHvjE+eYk07Q+wNro\
ZvPUEJYnbBlECwyAFVENSZXf0DW5S5AHy2F2SVaa7NMKQ0cqeaKoLYZcz4+Nmxm2FEUIfQaw9UfsAEIiyQYF0IQqDcHlVrQWXC2YUHGM8wKvJic\
Nw4A55gviXd/kF4DHjKTik0A0vhcwvsq+P7WHxSjCAPatipNrOza0uK7P2g92IrTC+NSzhXiIFHEXGTyWqsrjCI4GwRkEulDBNm2YjWX1nWWATk\
ZyiOZSVIxVAQSBXp1B1qZpnWjk+b00ut9itFMEeoQtI3Dx+s3QfZNFdd0XeTWl23KE6lOLuHf+yXycfWHm+EimEX6T4LRLVyFdJsCwfcqPd7690\
eD8IWgFOqi/yH4of8DPxTiD/8AmF34y2XCvLIAAAAASUVORK5CYII='

# this writes the mario-sheet.png to disk if it doen't exist
if not os.path.exists("mario-sheet.png"):
    f = open("mario-sheet.png", "wb")
    f.write(base64.b64decode(MARIO_SPRITESHEET))
    f.close()

class spritesheet:
    def __init__(s, filename, cols, rows=1, scale=False):
        source = pygame.image.load(filename).convert_alpha()
        if scale:
            w, h = source.get_rect().size
            source = pygame.transform.scale(source, (w * scale, h * scale))
        size = source.get_rect().size
        s.w, s.h = size[0] // cols, size[1] // rows
        s.sprites = [source.subsurface(((index % cols * s.w, index // cols * s.h), (s.w, s.h))) for index in range(cols * rows)]

    def size(s):
        return (s.w, s.h)

    def blit(s, index, xy):
        global PDS
        PDS.blit(s.sprites[int(index)], xy)

class mario:
    def __init__(s, spawnPoint):
        global MARIO_SPRITES, MARIO_JUMPING_RIGHT
        s.xy = Vector2(spawnPoint)
        s.Rect = (s.xy, MARIO_SPRITES.size())
        s.frame = MARIO_STANDING_RIGHT
        s.vel = Vector2(0, 0)
        s.status = s.standing

    def draw(s):
        global MARIO_SPRITES
        MARIO_SPRITES.blit(s.frame, s.xy)

    def standing(s):
        global MARIO_WALKING_RIGHT, MARIO_WALKING_LEFT
        if s.keys[pygame.K_RIGHT]:
            s.frame = MARIO_WALKING_RIGHT[0]
            s.status = s.walking_right
        elif s.keys[pygame.K_LEFT]:
            s.frame = MARIO_WALKING_LEFT[0]
            s.status = s.walking_left

    def walking_right(s):
        global MARIO_WALKING_RIGHT, MARIO_SKIDDING_RIGHT, MARIO_MAX_SPEED, MARIO_ACCELERATION
        if s.keys[pygame.K_LEFT] and s.vel.x > 0:
            s.frame = MARIO_SKIDDING_RIGHT
            s.status = s.skidding_right
            return
        if s.keys[pygame.K_RIGHT]:
            s.vel.x += MARIO_ACCELERATION
            if s.vel.x > MARIO_MAX_SPEED:
                s.vel.x = MARIO_MAX_SPEED
        else:
            s.vel.x -= 0.1
            if s.vel.x < 0:
                s.vel.x = 0
                s.frame = MARIO_STANDING_RIGHT
                s.status = s.standing
                return
        s.frame += 0.2
        if s.frame > MARIO_WALKING_RIGHT[1]:
            s.frame = MARIO_WALKING_RIGHT[0]

    def skidding_right(s):
        global MARIO_WALKING_RIGHT, MARIO_WALKING_LEFT, MARIO_DEACCELERATION
        if s.keys[pygame.K_RIGHT]:
            s.frame = MARIO_WALKING_RIGHT[0]
            s.status = s.walking_right
            return
        s.vel.x -= MARIO_DEACCELERATION
        if s.vel.x < 0:
            s.frame = MARIO_WALKING_LEFT[0]
            s.status = s.walking_left

    def walking_left(s):
        global MARIO_WALKING_LEFT, MARIO_SKIDDING_LEFT, MARIO_MAX_SPEED, MARIO_ACCELERATION
        if s.keys[pygame.K_RIGHT] and s.vel.x < 0:
            s.frame = MARIO_SKIDDING_LEFT
            s.status = s.skidding_left
            return
        if s.keys[pygame.K_LEFT]:
            s.vel.x -= MARIO_ACCELERATION
            if s.vel.x < -MARIO_MAX_SPEED:
                s.vel.x = -MARIO_MAX_SPEED
        else:
            s.vel.x += 0.1
            if s.vel.x > 0:
                s.vel.x = 0
                s.frame = MARIO_STANDING_LEFT
                s.status = s.standing
                return
        s.frame += 0.2
        if s.frame > MARIO_WALKING_LEFT[1]:
            s.frame = MARIO_WALKING_LEFT[0]

    def skidding_left(s):
        global MARIO_WALKING_LEFT, MARIO_WALKING_RIGHT, MARIO_DEACCELERATION
        if s.keys[pygame.K_LEFT]:
            s.frame = MARIO_WALKING_LEFT[0]
            s.status = s.walking_left
            return
        s.vel.x += MARIO_DEACCELERATION
        if s.vel.x > 0:
            s.frame = MARIO_WALKING_RIGHT[0]
            s.status = s.walking_right

    def update(s):
        s.keys = pygame.key.get_pressed()
        s.status()
        s.xy += s.vel

BLACK = (0, 0, 0)
WHITE = (255, 255, 255)

GRAVITY = Vector2(0, 0.1)

pygame.init()
PDR = Rect(0, 0, 1280, 720)
PDS = pygame.display.set_mode(PDR.size) #, pygame.FULLSCREEN | pygame.SCALED)

MARIO_SPRITES = spritesheet("mario-sheet.png", 6, 2, 3)
MARIO_STANDING_RIGHT = 0
MARIO_WALKING_RIGHT = (1, 4)
MARIO_JUMPING_RIGHT = 4
MARIO_SKIDDING_RIGHT = 5
MARIO_STANDING_LEFT = 6
MARIO_WALKING_LEFT = (7, 10)
MARIO_JUMPING_LEFT = 10
MARIO_SKIDDING_LEFT = 11
MARIO_MAX_SPEED = 4
MARIO_DEACCELERATION = 0.15
MARIO_ACCELERATION = 0.1

MARIO = mario(PDR.center)

exitDemo = False
pause = False # press p to pause
while not exitDemo:

    # handle the events
    events = pygame.event.get()
    for event in events:
        if event.type == pygame.QUIT or (event.type == pygame.KEYDOWN and event.key == pygame.K_ESCAPE):
            exitDemo = True
        if event.type == pygame.KEYDOWN and event.key == pygame.K_p:
            pause = 1 - pause

    if pause: continue

    PDS.fill(BLACK)

    MARIO.draw()
    MARIO.update()

    pygame.display.update()
    pygame.time.Clock().tick(60)

pygame.quit()