why can't my code detect button down on a joystick

Question

I am using the pygame.joystick method to use joysticks in my game, however, my code can only detect the model of the joystick, and cannot detect what buttons are down.

import pygame

# Define some colors
BLACK    = (   0,   0,   0)
WHITE    = ( 255, 255, 255)

# This is a simple class that will help us print to the screen
# It has nothing to do with the joysticks, just outputting the
# information.
class TextPrint:
    def __init__(self):
        self.reset()
        self.font = pygame.font.Font(None, 20)

    def print(self, screen, textString):
        textBitmap = self.font.render(textString, True, BLACK)
        screen.blit(textBitmap, [self.x, self.y])
        self.y += self.line_height

    def reset(self):
        self.x = 10
        self.y = 10
        self.line_height = 15

    def indent(self):
        self.x += 10

    def unindent(self):
        self.x -= 10


pygame.init()

# Set the width and height of the screen [width,height]
size = [500, 700]
screen = pygame.display.set_mode(size)

pygame.display.set_caption("My Game")

#Loop until the user clicks the close button.
done = False

# Used to manage how fast the screen updates
clock = pygame.time.Clock()

# Initialize the joysticks
pygame.joystick.init()

# Get ready to print
textPrint = TextPrint()

# -------- Main Program Loop -----------
while done==False:
    # EVENT PROCESSING STEP
    for event in pygame.event.get(): # User did something
        if event.type == pygame.QUIT: # If user clicked close
            done=True # Flag that we are done so we exit this loop

        # Possible joystick actions: JOYAXISMOTION JOYBALLMOTION JOYBUTTONDOWN JOYBUTTONUP JOYHATMOTION
        if event.type == pygame.JOYBUTTONDOWN:
            print("Joystick button pressed.")
        if event.type == pygame.JOYBUTTONUP:
            print("Joystick button released.")
        print('EVENT')


    # DRAWING STEP
    # First, clear the screen to white. Don't put other drawing commands
    # above this, or they will be erased with this command.
    screen.fill(WHITE)
    textPrint.reset()

    # Get count of joysticks
    joystick_count = pygame.joystick.get_count()

    textPrint.print(screen, "Number of joysticks: {}".format(joystick_count) )
    textPrint.indent()

    # For each joystick:
    for i in range(joystick_count):
        joystick = pygame.joystick.Joystick(i)
        joystick.init()

        textPrint.print(screen, "Joystick {}".format(i) )
        textPrint.indent()

        # Get the name from the OS for the controller/joystick
        name = joystick.get_name()
        textPrint.print(screen, "Joystick name: {}".format(name) )

        # Usually axis run in pairs, up/down for one, and left/right for
        # the other.
        axes = joystick.get_numaxes()
        textPrint.print(screen, "Number of axes: {}".format(axes) )
        textPrint.indent()

        for i in range( axes ):
            axis = joystick.get_axis( i )
            textPrint.print(screen, "Axis {} value: {:>6.3f}".format(i, axis) )
        textPrint.unindent()

        buttons = joystick.get_numbuttons()
        textPrint.print(screen, "Number of buttons: {}".format(buttons) )
        textPrint.indent()

        for i in range( buttons ):
            button = joystick.get_button( i )
            textPrint.print(screen, "Button {:>2} value: {}".format(i,button) )
        textPrint.unindent()

        # Hat switch. All or nothing for direction, not like joysticks.
        # Value comes back in an array.
        hats = joystick.get_numhats()
        textPrint.print(screen, "Number of hats: {}".format(hats) )
        textPrint.indent()

        for i in range( hats ):
            hat = joystick.get_hat( i )
            textPrint.print(screen, "Hat {} value: {}".format(i, str(hat)) )
        textPrint.unindent()

        textPrint.unindent()


    # ALL CODE TO DRAW SHOULD GO ABOVE THIS COMMENT

    # Go ahead and update the screen with what we've drawn.
    pygame.display.flip()

    # Limit to 20 frames per second
    clock.tick(20)

# Close the window and quit.
# If you forget this line, the program will 'hang'
# on exit if running from IDLE.
pygame.quit ()

Here is the code I used to test my joystick: here Sorry, I had to make it a drive document.

Answer 1

The code is initialising the joysticks every update-loop. It's only necessary to initialise it once. I think it's best to move all your initialisation code into a single function. I suspect the constant re-initialisation of the joystick is interfering its proper functioning.

def initialiseJoysticks():
    """Initialise all joysticks, returning a list of pygame.joystick.Joystick"""
    joysticks = []              # for returning

    # Initialise the Joystick sub-module
    pygame.joystick.init()

    # Get count of joysticks
    joystick_count = pygame.joystick.get_count()

    # For each joystick:
    for i in range( joystick_count ):
        joystick = pygame.joystick.Joystick( i )
        joystick.init()
        # NOTE: Some examples discard joysticks where the button-count
        #       is zero.  Maybe this is a common problem. 
        joysticks.append( joystick )

    # TODO: Print all the statistics about the joysticks
    if ( len( joysticks ) == 0 ):
        print( "No joysticks found" )
    else:
        for i,joystk in enumerate( joysticks ):
            print("Joystick %d is named [%s]" % ( i, joystk.get_name() ) )
            # etc.

    return joysticks

Then in your main code, call this initialiser once, outside the loop.

done = False
all_joysticks = initialiseJoysticks()

# -------- Main Program Loop -----------
while not done:
    # EVENT PROCESSING STEP
    for event in pygame.event.get(): # User did something
        if event.type == pygame.QUIT: # If user clicked close
            done=True # Flag that we are done so we exit this loop

        # Possible joystick actions: JOYAXISMOTION JOYBALLMOTION JOYBUTTONDOWN JOYBUTTONUP JOYHATMOTION
        elif event.type == pygame.JOYAXISMOTION:
            axis = [ 'X', 'Y' ]
            print( "joystick: %d, movement: %4.2f in the %s-axis" % ( event.joy, event.value, axis[event.axis] ) )
        elif event.type == pygame.JOYBUTTONDOWN:
            #print( "Joystick button pressed." )
            pass
        elif event.type == pygame.JOYBUTTONUP:
            print( 'joystick: %d, button: %d' % ( event.joy, event.button ) )

    # DRAWING STEP
    # First, clear the screen to white. Don't put other drawing commands
    # above this, or they will be erased with this command.
    screen.fill( WHITE )

    # Go ahead and update the screen with what we've drawn.
    pygame.display.flip()

    # Limit to 20 frames per second
    clock.tick( 20 )

# exit
pygame.quit()