save project

my_tree.py

@@ -13,12 +13,15 @@ pen.backward(150)    # 后退
 pen.down()
 def s(n):
     if n>=0:
+        pen.pensize(n/10)
         pen.forward(n)
-        pen.right(30)
-        s(n-10)
-        pen.left(60)
-        s(n-10)
-        pen.right(30)
+        angle=random.random(0,30)
+        leng=random.random(1,15)
+        pen.right(angle)
+        s(n-leng)
+        pen.left(2*angle)
+        s(n-leng)
+        pen.right(angle)
         pen.up()
         pen.backward(n)
         pen.down()