save project

my_tree.py

 import turtle
 import turtle
-
+# 移动到起点
+def tree(n):
+    if n>=0:
+        pen.forward(n)    # 后退
+        pen.right(30)
+        tree(n-10)
+        pen.left(60)
+        tree(n-10)
+        pen.right(30)
+        pen.up()
+        pen.backward(n)
+        pen.down()
 pen = turtle.Turtle()
 pen = turtle.Turtle()
 pen.color('sienna')
 pen.color('sienna')
 # 画布大小
 # 画布大小
 w = turtle.Screen()
 w = turtle.Screen()
 w.bgcolor('wheat')      # wheat小麦
 w.bgcolor('wheat')      # wheat小麦
-
-# 移动到起点
 pen.left(90)
 pen.left(90)
 pen.up()
 pen.up()
-pen.backward(150)    # 后退
+pen.backward(150)
 pen.down()
 pen.down()
-pen.forward(100)
-pen.right(30)
-pen.forward(50)
-pen.backward(50) 
-pen.left(60)
-pen.forward(50)
-
+tree(60)
 turtle.done()
 turtle.done()
+
+