How to reduce only a single life in a while loop in pygame?

Question

So basically I am making a game in which, if the player touches the enemy, the player loses a life. I tried to do it by:

if player.rect.colliderect(enemy.rect):
    life -= 1

This code is present in while loop, so it keeps decreasing the life. I just want it to decrease the life by only one.

Any help would be appreciated.

Thanks

Answer 1

Add an attribute collide to the your "Enemy" class:

class Enemy(pygame.sprite.Sprite):
    def __init__(self, ...):
        # [...]

        self.collide = False

Implement the following logic:

• If an enemy collides with the player and self.collide is set, do nothing.

• If an enemy collides with the player and self.collide is not set, set self.collide = True and decrement life.

• If an enemy does not collide with the player, set self.collide = False.

while run:
    # [...]

    for enemy in enemies:

        if player.rect.colliderect(enemy.rect):
            
            # If an enemy collides with the player and `self.collide` is set, do nothing.
            if not self.collide:
                # If an enemy collides with the player and `self.collide` is not set, 
                # set `self.collide = True` and decrement `life`.
                self.collide = True
                life -= 1
                
        else:
            # If an enemy does not collide with the player, set `self.collide = False`.
            self.collide = False

This logic means that live is only decremented when the enemy hits the player for the first time. The enemy must leave the player's area for a collision to be counted again.