save project

my_tree.py

 import turtle
+import random
 
 pen = turtle.Turtle()
 pen.color('sienna')
@@ -12,7 +13,17 @@ pen.up()
 pen.backward(150)    # 后退
 pen.down()
 def tree(n):
+    if n >= 0:
+        pen.speed(10000)
         pen.forward(n)
+        pen.right(30)
+        tree(n-10)
+        pen.left(60)
+        tree(n-10)
+        pen.right(30)
+        pen.up()
+        pen.backward(n)
+        pen.down()
        
 tree(100)