A Keyboard is the primary input device of every PC computer. As for game programmers, it is important to not that only high quality keyboards can handle more than 2 pressed keys at the same time correctly.

See Rollover for more information. The of keys not correctly interpreted, ignored or even false keyboard signals (ghost key) interpreted is hardware-related.

User yipyip wrote a very cool pygame program to test your keyboard. Hint: press <key>w</key>, <key>s</key>, and <key>d</key> at the same time.

#!/usr/bin/env python

####

import pygame as pyg

####

class Display(object):
          

  def __init__(self, width, height, fsize):

    pyg.init()
    self.screen = pyg.display.set_mode((width, height), pyg.DOUBLEBUF)
    self.font = pyg.font.Font(None, fsize)
    self.clock = pyg.time.Clock()
    self.fsize = fsize
    self.events = []
    self.pygkeys = [k for k in pyg.__dict__.keys() if k.startswith('K_')]

   
  def dispatch_events(self):

    #print pyg.key.get_pressed()
    self.act_keys = ''.join(('*' if c else '.' for c in pyg.key.get_pressed()))

    events = pyg.event.get()
    for ev in events:
      print ev
      if ev.type == pyg.QUIT:
        return 'q'
      if ev.type == pyg.KEYUP:
        self.events = []
      if ev.type == pyg.KEYDOWN:
        print ev.scancode
        self.events.append(ev.key)
        if ev.key == pyg.K_ESCAPE:
          return 'q'

 
  def draw_text(self, x, y, text):

    surface = self.font.render(text, True, (0, 255, 0))
    self.screen.blit(surface, (x, y))


  def draw_all(self):

    self.draw_text(0, 0, self.act_keys)
    ks = []
    for ev in self.events:
      for k in self.pygkeys:
        if pyg.__dict__[k] == ev:
          ks.append(k)
          break
        
    #print ks
    self.draw_text(0, self.fsize, (' ' * 5).join('%s' % k for k in ks))
    

       
  def flip(self):

    self.clock.tick(70)
    pyg.display.flip()
    self.screen.fill((0,0,0))

####

class Controller(object):


  def __init__(self, width, height, fsize):

    self.display = Display(width, height, fsize)


  def run(self):

    while not self.display.dispatch_events() == 'q':
      self.display.draw_all()
      self.display.flip()

####
      
if __name__ == '__main__':

  Controller(1000, 40, 18).run()