save project

my_tree.py

@@ -14,7 +14,7 @@ pen.up()
 pen.backward(150)    # 后退
 pen.backward(150)    # 后退
 pen.down()
 pen.down()
 def tree(n):
 def tree(n):
-    if n<=0:
+    if n>=0:
         pen.speed(0)
         pen.speed(0)
         pen.forward(n)
         pen.forward(n)
         pen.right(30)
         pen.right(30)