save project

my_tree.py

@@ -13,3 +13,16 @@ pen.backward(150)    # 后退
 pen.down()
 
 turtle.done()
+
+ 
+def tree(n):
+    if n>=0:
+        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()
\ No newline at end of file