save project

my_tree.py

 import turtle
 
+def tree(n):
+    if n>=0:
+      pen.forward(50)
+      pen.right(30)
+      tree(n-10)
+      pen.left(60)
+      tree(n-10)
+      pen.right(30)
+      pen.up()
+      pen.backward(50)
+      pen.down()
 pen = turtle.Turtle()
 pen.color('sienna')
-turtle.left(90)
-turtle.forward(50)
-turtle.right(30)
-turtle.forward(30)
-turtle.penup()
-turtle.backward(30)
-turtle.left(60)
-turtle.pendown()
-turtle.forward(30)
+w = turtle.Screen()
+w.bgcolor('wheat')
 
 
 
@@ -24,5 +28,5 @@ pen.left(90)
 pen.up()
 pen.backward(150)    # 后退
 pen.down()
-
+tree(60)
 turtle.done()