[Tutor] invalid literal for int error in Game loop

[Ciaran Mooney]

HI All,

Was hoping someone could help me with a problem I am having programming a game using pygame.

I am trying to return a variable with a integer value defined by user input from a function.

Basically the idea is to allow the player to select the level of difficulty by selecting from a choice of keys, each key corresponding too  the number of frames per second. The function code is as follows:

def difficultyLevel():
    FPS = ''
    windowSurface = pygame.display.set_mode((WINDOWWIDTH, WINDOWHEIGHT),pygame.FULLSCREEN)
    windowSurface.fill(BACKGROUNDCOLOUR)
    drawText('LEVEL OF PLAY', font3, windowSurface, (WINDOWWIDTH/6), (WINDOWHEIGHT/6)) 
    drawText('B: Your an absoulute Begineer', font3, windowSurface, (WINDOWWIDTH/6)-100, (WINDOWHEIGHT/6)+100)
    drawText('M: Not Too Snazy', font3, windowSurface, (WINDOWWIDTH/6)-100, (WINDOWHEIGHT/6)+150)
    drawText('H: Deathwish' ,font3,windowSurface, (WINDOWWIDTH/6)-100, (WINDOWHEIGHT/6)+200)
    pygame.display.update()
    

       
    for event in pygame.event.get():
        if event.type == QUIT:
            terminate()
                
        if event.type == KEYDOWN:
            if event.key == ord('b'):
                FPS = 30
            elif event.key == ord('m'):
                FPS = 70
            elif event.key == ord('h'):
                FPS = 120
    

    return FPS

The function is then called and FPS converted too a  integer value in the main game loop as follows:

topScore = 0
while True:
    #set up the game and all intial key and mouse movement values as false
    
    baddies = [] #baddies as a empy list
    score = 0
    etc

    FPS = int(difficultyLevel())
    
FPS is then used within the game loop  to allow for number of frames per second in:

mainClock.tick(FPS)

However I keep getting the following error:

ValueError: invalid literal for int() with base 10: ''


Please note I am a absolute beoingeer in programming and have had no formal education to date so please excuse anything I may of left out !!


Thanks
Ciaran

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