auto save

my_tree.py

 import turtle
+import random
 pen = turtle.Turtle()
 pen.color('sienna')      # sienna黄土色
 # 画布大小
 w = turtle.Screen()
 w.bgcolor('wheat')      # wheat小麦色
-pen.pensize(3)
 # 移动到起点
 pen.left(90)
 pen.up()
@@ -12,8 +12,11 @@ pen.backward(150)    # 后退
 pen.down()
 
 def tree(n):
-    if n>=50:
+    if n>=0:
+        pen.pensize(n/10)
         pen.forward(n)
+        angle = random.randint(0,30)    # 随机角度
+        length = random.randint(1,15)
         pen.right(30)
         tree(n-10)
         pen.left(60)
@@ -22,6 +25,7 @@ def tree(n):
         pen.up()
         pen.backward(n)
         pen.down()
+    if n
 tree(100)
 
 pen.hideturtle()