Added tower upgrading

Issue #8 (pylint problem resolved with this change)

Upgrade system not done, only simplel upgrading added

game/tower.py

@@ -2,6 +2,7 @@
 import math
 import pygame as pg
 from game.util import tile_to_pixel
+from game.upgrade_data import UPGRADE_DATA
 
 class Tower(pg.sprite.Sprite):
     # pylint: disable=too-many-instance-attributes
@@ -20,23 +21,25 @@ class Tower(pg.sprite.Sprite):
         pos (tuple): World-space pixel centre position.
         tile_pos (tuple): Grid position the tower occupies.
     """
-    def __init__(self, game, pos, tile_pos, type, range, level=1):
+    def __init__(self, game, pos, tile_pos, tower_type, level=1):
         super().__init__()
         self.game = game
-        self.type = type
-        self.image = self.game.assets[type]
+        self.type = tower_type
+        self.image = self.game.assets[tower_type]
         self.rect = self.image.get_rect()
         self.rect.center = pos
 
-        self.range = range
+        self.level = level
+
+        self.range = UPGRADE_DATA[self.type][self.level]["range"]
+        self.fire_rate = UPGRADE_DATA[self.type][self.level]["fire_rate"]
+        self.damage = UPGRADE_DATA[self.type][self.level]["damage"]
+
         self.selected = False
         self.angle = 0
         self.target = None
 
-        self.fire_rate = 180      # frames between shots — tune to taste
         self.fire_cooldown = 0
-        self.damage = 50
-
         self.pos = pos
         self.tile_pos = tile_pos
         self.level = level
@@ -152,6 +155,19 @@ class Tower(pg.sprite.Sprite):
         self.animation.play_animation()
         self.fire_cooldown = self.fire_rate
 
+    def upgrade(self):
+        """Upgrade the tower by one Level"""
+        print("upgrade")
+        next_level = self.level + 1
+        data = UPGRADE_DATA[self.type]
+        if next_level not in data:
+            return
+
+        self.level = next_level
+        self.damage    = data[next_level]['damage']
+        self.fire_rate = data[next_level]['fire_rate']
+        self.range     = data[next_level]['range']
+
 class TowerGroup(pg.sprite.Group):
     """Sprite group that delegates rendering and updates to each tower."""