Python: Game: Test Typing speed

Now the person who wrote the book is a bit of a sense of responsibility, recently read a few books, where the code is wrong.

Recently obsessed with Python games, bought "Getting started with Python game programming" [US] Jonathan S. Harbour a book to see.

In the fourth chapter: Bomb catcher game, the program code to test typing speed is seriously wrong.

Change the program screen randomly display a letter, the key to enter the letter randomly displayed next, calculate the average one minute can enter how many letters, the original code in the calculation of the speed of a piece of error, with my revised code

ImportSYSImportRandomImport TimeImportPygame fromPygame.localsImport*defPrint_text (font, x, y, text, color= (255, 255, 255)): Imgtext=font.render (text, True, color) screen.blit (Imgtext, (x, y)) pygame.init () screen= Pygame.display.set_mode ((600, 500)) Pygame.display.set_caption ('Keyboard Demo') Font1= Pygame.font.Font (None, 24) Font2= Pygame.font.Font (None, 200) White= (255, 255, 255) Yellow= (255, 255, 0) Key_flag=Falsecorrect_answer= 97#aseconds = 11score=0speed=0clock_start=0game_over=True whileTrue: forEventinchpygame.event.get ():ifEvent.type = =QUIT:sys.exit ()elifEvent.type = =Keydown:key_flag=TrueelifEvent.type = =Keyup:key_flag=False Keys= Pygame.key.get_pressed ()#Keys is a tuple, poor up all the keys, not pressed to 0, press 1    ifKeys[k_escape]: sys.exit ()ifKeys[k_return]:ifGame_over:game_over=False Clock_start=Time.time () score=0 seconds= 11 Speed=0 Clock=Clock_startif  notgame_over:current= Time.time ()-Clock_startifSeconds <Current:game_over=TrueElse:            ifKeys[correct_answer]: Correct_answer= Random.randint (97, 122) Clock_start=Time.time () score+ = 1 Speed= * Score/(Clock_start-clock) Screen.fill ((0,100, 0)) Print_text (font1, 0, 0,"Let's see how fast can type!") Print_text (font1, 0,20,"Try to keep up for ten seconds ...")    ifKey_flag:print_text (Font1,500, 0,"<key>")    if  notGame_over:print_text (font1, 0,80,"Time :"+ str (int (seconds-Current)) ) Print_text (font1, 0,100,"Speed :"+ str (int (speed)) +"Letters/min")    ifGame_over:print_text (font1, 0,160,"Press Enter to start ...") Print_text (font2, 0,, Chr (correct_answer-32), yellow) pygame.display.update ()

Python: Game: Test Typing speed