save project

my_tree.py

 import turtle
+import random
 
 pen = turtle.Turtle()
 pen.color('sienna')
@@ -12,4 +13,21 @@ pen.up()
 pen.backward(150)    # 后退
 pen.down()
 
+def tree(n):
+    if n>=0:
+        pen.pensize(n/10)
+        pen.forward(n)
+        angle = random.randint(0,30)
+        length = random.randint(1,15)
+        pen.right(angle)
+        tree(n-length)
+        pen.left(2*angle)
+        tree(n-length)
+        pen.right(angle)
+        pen.up()
+        pen.backward(n)
+        pen.down()
+
+tree(60)
+
 turtle.done()