Jumper

import pygame
import random

GRAVITY = 1
PLAYER_VELOCITY = 5
JUMP_POWER = 20
HEIGHT = 901
WIDTH = 500
backgroundColour = (0,215,62)
platformColour = (0,255,0)
# self.image = substitute for actual image
class Platform(pygame.sprite.Sprite):
    def __init__(self, y,pl = 100):
        super().__init__()
        platheight = 10
        platlength = pl
        self.image = pygame.Surface((platlength,platheight))
        self.image.fill(platformColour)
        self.rect = self.image.get_rect()  # <-- makes rectangle
        self.rect.left = (random.randrange(0,WIDTH - platlength))
        self.rect.centery = y

class player(pygame.sprite.Sprite):
    def __init__(self):
        super().__init__()

        self.image = pygame.Surface((50, 90))
        self.image.fill((130, 230, 99))
        self.rect = self.image.get_rect()
        self.rect.center = (485,550)
        self.dx = 0
        self.dy = 0
        self.in_air = True
        self.gravity = GRAVITY

    def update(self):
        self.dx = 0
        keys = pygame.key.get_pressed()
        if keys [pygame.K_a]:
            self.dx = -PLAYER_VELOCITY
        if keys [pygame.K_d]:
            self.dx = PLAYER_VELOCITY
        if keys [pygame.K_SPACE] and not self.in_air:
            self.jump()
        self.dy += self.gravity
        self.rect.move_ip(self.dx,self.dy)

    def jump(self):
        keys = pygame.key.get_pressed() #makes the key function
        if keys [pygame.K_SPACE]:
            self.dy = -JUMP_POWER
            self.in_air = True
            self.gravity = GRAVITY




pygame.init()
window = pygame.display.set_mode((WIDTH,HEIGHT)) #makes window
run = True
clock = pygame.time.Clock() # <-- makes a clock
elements = pygame.sprite.Group() #group where all objects are stored
platforms = pygame.sprite.Group()
for x in range(5): #value of x will be 0 1 2 3 4 5
    p = Platform((x+1)*150)
    elements.add(p)
    platforms.add(p)
base = Platform(HEIGHT-20, WIDTH - 1)
elements.add(base) #adds base to element group
platforms.add(base) #adds to platforms
layer = player()
elements.add(layer)
while run:
    window.fill(backgroundColour)
    clock.tick(60) # <-- sets FPS to 60
    for event in pygame.event.get(): # <-- gives you all events
        if event.type == pygame.QUIT: # <-- if the event is that you close the program
            run = False # <--shuts down windowplatforms, F
    plat = pygame.sprite.spritecollideany(layer, platforms)
    if plat and layer.dy > 0 and layer.rect.centery <= plat.rect.top:
        layer.in_air = False
        layer.gravity = 0 # accleration
        layer.dy = 0 # velocity
        layer.rect.bottom = plat.rect.top
    else:
        layer.gravity = GRAVITY
    elements.update() # updates all objects in element group
    elements.draw(window) #places objects from elements group into window
    pygame.display.update()