save project

my_tree.py

@@ -5,6 +5,7 @@ pen.color('sienna')
 # 画布大小
 w = turtle.Screen()
 w.bgcolor('wheat')      # wheat小麦
+pen.speed(0)
 
 # 移动到起点
 pen.left(90)
@@ -12,17 +13,19 @@ pen.up()
 pen.backward(150)    # 后退
 pen.down()
 
-pen.forward(100)  #主树干
-pen.right(30)     #右树干
-pen.forward(50)
-pen.penup()
-pen.forward(-50)
-pen.pendown()
-pen.left(60)      #左树干
-pen.forward(50)
-pen.penup()       #返回
-pen.forward(-50)
-pen.right(30)
-pen.forward(-100)
-pen.pendown()
+def tree(n):
+    if n>=50:
+        pen.forward(n)
+        pen.right(30)
+        tree(n-10)
+        pen.left(60)
+        tree(n-10)
+        pen.right(30)
+        pen.penup()
+        pen.backward(n)
+        pen.down()
+
+tree(100)
+
+
 turtle.done()