save project

my_tree.py

@@ -3,8 +3,9 @@ import turtle
 pen = turtle.Turtle()
 pen = turtle.Turtle()
 pen.color('sienna')
 pen.color('sienna')
 # 画布大小
 # 画布大小
+pen.pensize(6)
 w = turtle.Screen()
 w = turtle.Screen()
-w.bgcolor('wheat')      # wheat小麦
+w.bgcolor('black')      
 
 
 # 移动到起点
 # 移动到起点
 pen.left(90)
 pen.left(90)
@@ -12,15 +13,17 @@ pen.up()
 pen.backward(150)    # 后退
 pen.backward(150)    # 后退
 pen.down()
 pen.down()
 
 
-pen.forward(100)
-pen.right(30)
-pen.forward(50)
-pen.goto(0,-50)
-pen.left(60)
-pen.forward(50)
-pen.penup()
-pen.goto(0,-150)
-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.pendown()
+tree(100)
 turtle.done()    
 turtle.done()