Untitled

import pygame, sys

class Player(pygame.sprite.Sprite) :
    def __init__(self):
        super().__init__()
        self.image =  pygame.Surface((40,40))
        self.image.fill((240,240,240))
        self.rect = self.image.get_rect(center = (400,400))
        self.current_health = 200
        self.target_health = 500
        self.maximum_health = 1000
        self.health_bar_length = 400
        self.health_ratio = self.maximum_health /  self.health_bar_length
        self.health_change_speed = 5

    def update(self):
            # self.basic_health()
            self.advanced_health()
    
    def get_damage(self, amount):
        if self.target_health > 0:
             self.target_health -= amount
        if self.target_health <= 0:
             self.target_health = 0

    def get_health(self, amount):
        if self.target_health < self.maximum_health:
             self.target_health += amount
        if self.target_health >= self.maximum_health:
             self.target_health = self.maximum_health

    def basic_health(self):
         pygame.draw.rect(screen, (255, 0, 0),(10,10,self.target_health/self.health_ratio, 25)) # surface, color, rect, stroke width
         pygame.draw.rect(screen, (255, 255, 255),(10,10,self.health_bar_length,25), 4) 
  
    def advanced_health(self):
        transition_width = 0   #make it invisible
        transition_color = (255,0,0) # second health bar is always technically on screen
        
        if self.current_health < self.target_health:
            transition_color = (0, 255, 0)
            self.current_health += self.health_change_speed
            transition_width = int((self.target_health - self.current_health)/self.health_ratio)
        if self.current_health > self.target_health:
            transition_color = (255, 255, 0)
            self.current_health -= self.health_change_speed
            transition_width = int((self.current_health - self.target_health)/self.health_ratio)


        health_bar_rect = pygame.Rect(10,45,self.current_health/self.health_ratio,25)
        transition_bar_rect = pygame.Rect(health_bar_rect.right,45,transition_width,25)

        pygame.draw.rect(screen,(255,0,0),health_bar_rect)
        pygame.draw.rect(screen,transition_color,transition_bar_rect)
        pygame.draw.rect(screen,(255,255,255),(10,45, self.health_bar_length,25),4)
         

pygame.init()
screen = pygame.display.set_mode((800, 800))
clock = pygame.time.Clock()
player = pygame.sprite.GroupSingle(Player())

while True:
     for event in pygame.event.get():
          if event.type == pygame.QUIT:
               sys.exit()
          if event.type == pygame.KEYDOWN:
             if event.key == pygame.K_UP:
                  player.sprite.get_health(200)
          if event.type == pygame.KEYDOWN:
             if event.key == pygame.K_DOWN:
                  player.sprite.get_damage(200)  



     screen.fill((30,30,30))
     player.draw(screen)
     player.update()
     pygame.display.update()
     clock.tick(60)