[Tutor] break

[Mitya Sirenef]

On 03/14/2013 06:38 PM, Matthew Ngaha wrote:
> i cant seem to break out of  this loop. let me explain the variables you see:
 >
 > Enemy.ships = [] #an Enemy class variable that contains enemy ships
 > self.missiles = [] an instance variable that appends how many Visible
 > missiles my ship has fired
 > Enemy.rects = [] an Enemy class variable that represents a rectangle
 > for every ship in Enemy.ships
 > Explosion() = a class where explosions occur
 > QPoint() = is a pyqt function that takes a point x, y position as 
arguments
 >
 > im trying to destroy the ships if they hit a missile, even though i
 > use pyqt this is mainly python code
 >
 > if Enemy.ships:
 > for missile in self.missiles:
 > for rect in Enemy.rects:
 > if QPoint(missile.x + 5, missile.y) in rect:
 > explosion = Explosion(rect.x(), rect.y())
 > self.explosions.append(explosion)
 > break
 >
 > once the missile has hit 1 Enemy.rect i want to break and go to the
 > next missile so the missile is destroyed and doesnt hit another Enemy,
 > but for some reason the break i have isnt working and the same missile
 > sometimes is hitting 2 different rects on the same iteration. i have
 > done the same loop using a simple print statements on strings greater
 > than a certain length and it breaks correctly. anyone have any ideas
 > why the break isnt breaking out of the nested/inner loop but instead
 > continuing to loop through the Enemies?
 >


Yes, break statement exits only the current loop, not all loops.

One good approach is to have a separate function or method with
both loops:

def attack(self, Enemy):
     for missile in self.missiles:
         for rect in Enemy.rects:
             if QPoint(missile.x + 5, missile.y) in rect:
                 explosion = Explosion(rect.x(), rect.y())
                 self.explosions.append(explosion)
                 return


You could also set a flag and check it at the end of outer loop
and have a second break statement when the flag is set.

  HTH, -m



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