Re: [pygame] Fwd: [Tutor] A more Pythonic way to do this

[Shandy Brown <sjbrown@xxxxxxxxx>]

Hi Denise.

Sorry, I should have been clearer in my previous response.  I was trying
to imply with the snippet that you should change the constructor of the
enemy instances to be something like this:

class Enemy....
...
    def __init__( self, x, y, level ):
       self.level = level

       # this is the x that will be changed (you're probably using a rect
       # here or something)
       self.x = x
       # keep the initial x around for when we respawn
       self.initialx = x

       self.y = y
       # keep the initial x around for when we respawn
       self.initialy = y

       ...


Hopefully this is less, not more, confusing.

-sjbrown

On Wed, 6 Jul 2005, D. Hartley wrote:

> Shandy,
>
> The reason I was setting Enemy.initialx/y there was because I was
> using the createEnemies function to update the enemies' self.initialx
> values (when they are created) from 0 to whatever the starting
> position is, that way later I can reset each enemy's position to its
> initialx/y.
>
> Otherwise, I didnt even HAVE an initialx/y, and when I created the new
> enemies, I just did this:
>
> enemyship_sprites.add(Enemy((cols*60)+20, (rows*40)+30, level))
>
> The only reason to have  'newx' or 'initialx' was to find a way to
> store each ship's original position so that I could later return the
> ship to that original position.
>
> At this point, it's still returning ALL the enemyships to 0,0.
>
> (although it IS recording their initialx/y or newx/y values - I can
> see that from the print statement.  It's just that when I do the
>
>                     for enemy in (enemyship_sprites.sprites()):
>                         print enemy.initialx, enemy.initialy
>                         enemy.rect.centerx = enemy.initialx
>                         enemy.rect.centery = enemy.initialy
>
> code, it resets them all to 0,0 (the default value of
> initialx/initialy which I was trying to update in the createEnemies
> function by doing
>
> >     Enemy.initialx = (cols*60)+20
> >     Enemy.initialy = (rows*40)+30
> >     enemyship_sprites.add(Enemy(Enemy.initialx, Enemy.initialy, level))
> >     print Enemy.initialx,
> >     print Enemy.initialy
>
> Is there a way I can update this value and store it for each enemyship
> instance so I can refer to it later and reset the ship back to that
> position?  If I do
>
>      newX = (cols*60)+20
>      newY = (cols*60)+20
>      newEnemy = Enemy(newX, newY, level)
>      enemyship_sprites.add( newEnemy )
>
> It does make the createEnemies function somewhat clearer, but does not
> update the initialx/initialy.
>
> Please let me know if I'm being unclear about what I'm trying to do.
>
> Thanks,
> Denise
>
> On 7/6/05, Shandy Brown <sjbrown@xxxxxxxxx> wrote:
> > Hi Denise.
> >
> > I would just generally recommend the rule of thumb of not using class
> > attributes unless you really need them (implementing a Singleton or
> > something).  You're using class attributes again here:
> >
> > >     Enemy.initialx = (cols*60)+20
> > >     Enemy.initialy = (rows*40)+30
> > >     enemyship_sprites.add(Enemy(Enemy.initialx, Enemy.initialy, level))
> > >     print Enemy.initialx,
> > >     print Enemy.initialy
> >
> > Try to avoid writing Enemy.initalx anywhere in your code.  You could
> > rewrite the above as this:
> >
> >      newX = (cols*60)+20
> >      newY = (cols*60)+20
> >      newEnemy = Enemy(newX, newY, level)
> >      enemyship_sprites.add( newEnemy )
> >
> > It's also a bit more readable like this, I think.  (Another rule of thumb:
> > never sacrifice clarity for brevity)
> >
> > -sjbrown
> >
>