save project

my_tree.py

@@ -11,7 +11,8 @@ pen.left(90)
 pen.up()
 pen.up()
 pen.backward(150)    # 后退
 pen.backward(150)    # 后退
 pen.down()
 pen.down()
-pen.forward(100)
+
+pen.forward(100)    #绘制二叉树
 pen.right(30)
 pen.right(30)
 pen.forward(50)
 pen.forward(50)
 pen.backward(50)
 pen.backward(50)
@@ -20,6 +21,5 @@ pen.forward(50)
 pen.backward(50)
 pen.backward(50)
 pen.right(30)
 pen.right(30)
 pen.backward(100)
 pen.backward(100)
-pen.down()
 
 
 turtle.done()
 turtle.done()