save project

diy1.py

@@ -3,8 +3,12 @@
 每次移动都增加画笔移动的长度，并旋转91°，重复执行300次，查看效果
 """
 import turtle
+screen = turtle.Screen()
+screen.bgcolor("black")
+colors=["red","orange","yellow","green"]
 Pen = turtle.Pen()
 for i in range(1,300):
+    Pen.pencolor(colors[i%4])
     Pen.forward(i)
     Pen.right(91)
 Pen.hideturtle()