Adding examples

bubbles.py

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+from turtle import *
+from superturtle.animation import animate
+from random import random, seed
+
+HOW_FAR_BUBBLES_GO = 400
+
+def random_bubble_x():
+    return -200 + 400 * random()
+
+def random_bubble_y():
+    return -200 + 400 * random()
+
+def random_bubble_size():
+    return 10 + 40 * random()
+
+def generate_bubble_positions(n):
+    bubble_positions = []
+    for i in range(n):
+        x = random_bubble_x()
+        y = random_bubble_y()
+        r = random_bubble_size()
+        bubble_positions.append([x, y, r])
+    return bubble_positions
+
+def draw_bubbles(bubble_positions, frame):
+    for x, y, r in bubble_positions:
+        with frame.translate([x, y], [x, y + HOW_FAR_BUBBLES_GO]):
+            circle(r)
+
+number_of_bubbles = 25
+bubble_positions = generate_bubble_positions(number_of_bubbles)
+for frame in animate(100):
+    draw_bubbles(bubble_positions, frame)
+

turtle.py

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+def draw_turtle(frame):
+    # ...
+
+
+for frame in animate(100):
+    draw_turtle(frame)
+    draw_bubbles(frame)