pygame01.py

# ==================================================================
# Pygame example
#
# From: www.youtube.com/watch?v=i6xMBig-pP4
#       Pygame tutorial #1 - Basic Movement and Key Presses 
#
# ==================================================================

import pygame

pygame.init()

# window (display)

winx = 500
winy = 500

win = pygame.display.set_mode((winx,winy))

pygame.display.set_caption("Hay, It's me!!")

# rectangle

x      = 50        # initial x coordinate
y      = 50        # initial y coordinate
width  = 40        # rectangle width  
height = 60        # rectangle height
vel    = 5         # rectanble velocith (pixels)

# max/min rectangle movement coordinates
# (remember the rectangle's corrdinates are
#  in the upper left corner)

minx = 0
maxx = winx - width
miny = 0
maxy = winy - height

# loop until quit button

run = True

while run:

    # loop time delay

    pygame.time.delay(100)

    # check for events
    # if quit event,
    #    set the fun flag
    #    exit the for loop

    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            run = False
            continue

    # if run not true,
    #    break    - exit the while loop
    #    continue - skip the top of the while loop

    if not run:
        continue

    # process pressed arrow keys

    keys = pygame.key.get_pressed()

    if keys[pygame.K_LEFT]:       # left arrow
        x -= vel
        if x < minx:
            x = minx
    if keys[pygame.K_RIGHT]:      # right arrow
        x += vel
        if x > maxx:
            x = maxx
    if keys[pygame.K_UP]:         # up arrow
        y -= vel
        if y < miny:
            y = miny
    if keys[pygame.K_DOWN]:       # down arrow
        y += vel
        if y > maxy:
            y = maxy

    # blank (fill) the window
    # draw/redraw the rectangle
    # update the display (window)

    win.fill((0,0,0))
    pygame.draw.rect(win,(255,0,0),(x,y,width,height))
    pygame.display.update()

# quit the program

pygame.quit()