Data commit

Task/Sierpinski-pentagon/Python/sierpinski-pentagon.py

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+from turtle import *
+import math
+speed(0)      # 0 is the fastest speed. Otherwise, 1 (slow) to 10 (fast)
+hideturtle()  # hide the default turtle
+
+part_ratio = 2 * math.cos(math.radians(72))
+side_ratio = 1 / (part_ratio + 2)
+
+hide_turtles = True   # show/hide turtles as they draw
+path_color = "black"  # path color
+fill_color = "black"  # fill color
+
+# turtle, size
+def pentagon(t, s):
+  t.color(path_color, fill_color)
+  t.pendown()
+  t.right(36)
+  t.begin_fill()
+  for i in range(5):
+    t.forward(s)
+    t.right(72)
+  t.end_fill()
+
+# iteration, turtle, size
+def sierpinski(i, t, s):
+  t.setheading(0)
+  new_size = s * side_ratio
+
+  if i > 1:
+    i -= 1
+
+    # create four more turtles
+    for j in range(4):
+      t.right(36)
+      short = s * side_ratio / part_ratio
+      dist = [short, s, s, short][j]
+
+      # spawn a turtle
+      spawn = Turtle()
+      if hide_turtles:spawn.hideturtle()
+      spawn.penup()
+      spawn.setposition(t.position())
+      spawn.setheading(t.heading())
+      spawn.forward(dist)
+
+      # recurse for spawned turtles
+      sierpinski(i, spawn, new_size)
+
+    # recurse for parent turtle
+    sierpinski(i, t, new_size)
+
+  else:
+    # draw a pentagon
+    pentagon(t, s)
+    # delete turtle
+    del t
+
+def main():
+  t = Turtle()
+  t.hideturtle()
+  t.penup()
+  screen = t.getscreen()
+  y = screen.window_height()
+  t.goto(0, y/2-20)
+
+  i = 5       # depth. i >= 1
+  size = 300  # side length
+
+  # so the spawned turtles move only the distance to an inner pentagon
+  size *= part_ratio
+
+  # begin recursion
+  sierpinski(i, t, size)
+
+main()