auto save

diy.PY

 import turtle        # 导入turtle模块
 import turtle        # 导入turtle模块
 
 
 pen = turtle.Pen()  # 创建画笔
 pen = turtle.Pen()  # 创建画笔
+screen=turtle.Screen()                    # 从turtle模块中取出画布
+screen.bgcolor("black")                   # 用bgcolor()方法，将画布设为黑色
+colors=["green","red","orange","yellow"]   # 创建列表保存四种颜色
 for i in range(1,300):
 for i in range(1,300):
+    # 变量i对4求余后作为列表索引号并设为pencolor()参数
+    pen.pencolor(colors[i%4])
     pen.forward(i)    # 变量1表示画笔移动的距离
     pen.forward(i)    # 变量1表示画笔移动的距离
     pen.right(91)            # 右转91
     pen.right(91)            # 右转91
 pen.hideturtle()             # 隐藏画笔
 pen.hideturtle()             # 隐藏画笔