Python Programming - Concept of object movement using key arrow / WASD

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Pygame is look like a cartesius diagram that flipped vertically. Thats mean the Y-axis positive is on bottom and the negative Y-axis is on the top side. So the Pygame coordinate will look like this image.

Pygame Coordinate

From thats coordinate now we understand about how a object should do to move UP, DOWN, RIGHT, and LEFT. In this syntax i will shown to you how to make an object move using arrow or WASD keys.
here is the syntax:

import pygame,random,sys from pygame.locals import * xwindow = 800 ywindow = 600 midx = xwindow/2 midy = ywindow/2 BLACK = (0,0,0) WHITE = (255,255,255) FPS = 120 A = 0 # --- classes class Player(pygame.sprite.Sprite): def __init__(self, PlayerCoord): super(Player, self).__init__() for coord in PlayerCoord: x = coord['x'] y = coord['y'] PLAYER = pygame.draw.circle(DISPLAYSURF, BLACK,(x,y),(25),0) pygame.init() UP = 'up' DOWN = 'down' LEFT = 'left' RIGHT = 'right' STOP = 'stop' move = '' DISPLAYSURF = pygame.display.set_mode((xwindow,ywindow)) CLOCK = pygame.time.Clock() done = False playerCoord = [{'x':midx, 'y':midy}] while not done: DISPLAYSURF.fill(WHITE) for event in pygame.event.get(): if event.type == pygame.QUIT: done = True elif event.type == KEYDOWN: if event.key in (K_w, K_UP): move = UP elif event.key in (K_s, K_DOWN): move = DOWN elif event.key in (K_a, K_LEFT): move = LEFT elif event.key in (K_d, K_RIGHT): move = RIGHT elif event.key == K_SPACE: move = STOP elif event.type == KEYUP: pass else: pass Xcoord = (playerCoord[A]['x']) Ycoord = (playerCoord[A]['y']) if move == STOP: newCoord = {'x':Xcoord, 'y':Ycoord} elif move == UP and Ycoord>25: newCoord = {'x':Xcoord, 'y':Ycoord-2} elif move == DOWN and Ycoord<ywindow-25: newCoord = {'x':Xcoord, 'y':Ycoord+2} elif move == LEFT and Xcoord>25: newCoord = {'x':Xcoord-2, 'y':Ycoord} elif move == RIGHT and Xcoord<xwindow-25: newCoord = {'x':Xcoord+2, 'y':Ycoord} else: newCoord = {'x':Xcoord, 'y':Ycoord} del playerCoord[-1] playerCoord.insert(0,newCoord) Player(playerCoord) pygame.display.update() CLOCK.tick(FPS) #print Xcoord,Ycoord pygame.quit()

Now I will explain as many as i can.

•  Basic syntax   

You need to know about drawing circle, making a workspace, whats will happen when the key pressed, how to make color, and other. I dont need to describe this because you can learn about it in other basic post.

• Movement 

    Xcoord = (playerCoord[A]['x']) #This to for shorter the player X coordinate
    Ycoord = (playerCoord[A]['y']) #This to for shorter the player Y coordinate
    if move == STOP:
        newCoord = {'x':Xcoord, 'y':Ycoord}  #Dont add a move while looping
    elif move == UP and Ycoord>25:
        newCoord = {'x':Xcoord, 'y':Ycoord-2} #For each looping the Y coordinate is reduction by 2 point so the object will move to up
    elif move == DOWN and Ycoord<ywindow-25:
        newCoord = {'x':Xcoord, 'y':Ycoord+2} #For each looping the Y coordinate is added by 2 point so the object will move to down
    elif move == LEFT and Xcoord>25:
        newCoord = {'x':Xcoord-2, 'y':Ycoord} #For each looping the X coordinate is reduction by 2 point so the object will move to left
    elif move == RIGHT and Xcoord<xwindow-25:
        newCoord = {'x':Xcoord+2, 'y':Ycoord} #For each looping the X coordinate is added by 2 point so the object will move to right
    else:
        newCoord = {'x':Xcoord, 'y':Ycoord}  #Dont add a move while looping same as stop

I think that all a concept to create this basic movement. For more information you can ask me in comment. Thanks for visiting ^^