auto save

my_tree.py

 import turtle
-
+import random
 pen = turtle.Turtle()
 pen.color('sienna')
 # 画布大小
 w = turtle.Screen()
-w.bgcolor('wheat')      # wheat小麦
+w.bgcolor('wheat')      
 def tree(n):
     if n>=50:
         pen.forward(n)
-        pen.right(30)
+        angle = random.randint(0,30)
+        pen.right(angle)
         tree(n-10)
-        pen.left(30)
-        pen.left(30)
+        pen.left(2*angle)
         tree(n-10)
-        pen.right(30)
+        pen.right(angle)
         pen.up()
         pen.backward(n)
         pen.down()