1. import random
2. import time
3. import turtle
4.  
5. lasers = []
6. aliens = []
7.  
8. CANNON_STEP = 10
9. LASER_LENGTH = 20
10. LASER_SPEED = 10
11. ALIEN_SPAWN_INTERVAL = 1.2  # Seconds
12. ALIEN_SPEED = 2
13.  
14.  
15. # Draw cannon
16. def draw_cannon():
17.     cannon.clear()
18.     cannon.turtlesize(1, 4)  # Base
19.     cannon.stamp()
20.     cannon.sety(FLOOR_LEVEL + 10)
21.     cannon.turtlesize(1, 1.5)  # Next tier
22.     cannon.stamp()
23.     cannon.sety(FLOOR_LEVEL + 20)
24.     cannon.turtlesize(0.8, 0.3)  # Tip of cannon
25.     cannon.stamp()
26.     cannon.sety(FLOOR_LEVEL)
27.     window.update()
28.  
29.  
30. def move_left():
31.     new_x = cannon.xcor() - CANNON_STEP
32.     if new_x >= LEFT + GUTTER:
33.         cannon.setx(new_x)
34.         draw_cannon()
35.  
36.  
37. def move_right():
38.     new_x = cannon.xcor() + CANNON_STEP
39.     if new_x <= RIGHT - GUTTER:
40.         cannon.setx(new_x)
41.         draw_cannon()
42.  
43.  
44. def create_laser():
45.     laser = turtle.Turtle()
46.     laser.penup()
47.     laser.color(1, 0, 0)
48.     laser.hideturtle()
49.     laser.setposition(cannon.xcor(), cannon.ycor())
50.     laser.setheading(90)
51.     # Move laser to just above cannon tip
52.     laser.forward(20)
53.     # Prepare to draw the laser
54.     laser.pendown()
55.     laser.pensize(5)
56.  
57.     lasers.append(laser)
58.  
59.  
60. def move_laser(laser):
61.     laser.clear()
62.     laser.forward(LASER_SPEED)
63.     # Draw the laser
64.     laser.forward(LASER_LENGTH)
65.     laser.forward(-LASER_LENGTH)
66.  
67.  
68. def create_alien():
69.     alien = turtle.Turtle()
70.     alien.penup()
71.     alien.turtlesize(1.5)
72.     alien.setposition(
73.         random.randint(
74.             int(LEFT + GUTTER),
75.             int(RIGHT - GUTTER),
76.         ),
77.         TOP,
78.     )
79.     alien.shape("turtle")
80.     alien.setheading(-90)
81.     alien.color(random.random(), random.random(), random.random())
82.     aliens.append(alien)
83.  
84.  
85. # Remove alien
86. def remove_alien(alien):
87.     alien.clear()
88.     alien.hideturtle()
89.     aliens.remove(alien)
90.     turtle.turtles().remove(alien)
91.  
92.  
93. # Remove laser
94. def remove_laser(laser):
95.     laser.clear()
96.     laser.hideturtle()
97.     lasers.remove(laser)
98.     turtle.turtles().remove(laser)
99.  
100.  
101. # Remove sprite
102. def remove_sprite(sprite, sprite_list):
103.     sprite.clear()
104.     sprite.hideturtle()
105.     window.update()
106.     sprite_list.remove(sprite)
107.     turtle.turtles().remove(sprite)
108.  
109.  
110. window = turtle.Screen()
111. window.tracer(0)
112.  
113. window.setup(0.5, 0.75)
114. window.bgcolor(0.2, 0.2, 0.2)
115. window.title("The Real Python Space Invaders")
116.  
117. LEFT = -window.window_width() / 2
118. RIGHT = window.window_width() / 2
119. TOP = window.window_height() / 2
120. BOTTOM = -window.window_height() / 2
121. FLOOR_LEVEL = 0.9 * BOTTOM
122. GUTTER = 0.025 * window.window_width()
123.  
124. # Create laser cannon
125.  cann
126. cannon.penup()
127. cannon.color(1, 1, 1)
128. cannon.shape("square")
129. cannon.setposition(0, FLOOR_LEVEL)
130.  
131. # Create turtle for writing text
132. text = turtle.Turtle()
133. text.penup()
134. text.hideturtle()
135. text.setposition(LEFT * 0.8, TOP * 0.8)
136. text.color(1, 1, 1)
137.  
138. draw_cannon()
139. window.onkeypress(move_left, "Left")
140. window.onkeypress(move_right, "Right")
141. window.onkeypress(create_laser, "space")
142. window.onkeypress(turtle.bye, "q")
143. window.listen()
144.  
145. # Game loop
146. alien_timer = 0
147. score = 0
148. game_timer = time.time()
149. game_running = True
150. while game_running:
151.     time_elapsed = time.time() - game_timer
152.     text.clear()
153.     text.write(
154.         f"Time: {time_elapsed:5.1f}snScore: {score:5}",
155.          f 20, "bold"),
156.     )
157.     # Move all lasers
158.     for laser in lasers.copy():
159.         move_laser(laser)
160.         # Remove laser if it goes off screen
161.         if laser.ycor() > TOP:
162.             remove_sprite(laser, lasers)
163.             break
164.         # Check for collision with aliens
165.         for alien in aliens.copy():
166.             if laser.distance(alien) < 20:
167.                 remove_sprite(laser, lasers)
168.                 remove_sprite(alien, aliens)
169.                 score += 1
170.                 break
171.  
172.     # Spawn new aliens when time interval elapsed
173.     if time.time() - alien_timer > ALIEN_SPAWN_INTERVAL:
174.         create_alien()
175.         alien_timer = time.time()
176.  
177.     # Move all aliens
178.     for alien in aliens:
179.         alien.forward(ALIEN_SPEED)
180.         # Check for game over
181.         if alien.ycor() < FLOOR_LEVEL:
182.             game_running = False
183.             break
184.     window.update()
185.  
186. splash_text = turtle.Turtle()
187. splash_text.hideturtle()
188. splash_text.color(1, 1, 1)
189.  splash_text.write("GAME OVER", f 40, "bold"), align="center")
190.  
191. turtle.done()