save project

diy1.py

@@ -3,13 +3,13 @@
 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")
 pen = turtle.Pen()
+color = ["red","green","yellow","blue"]
 pen.speed(20)
-distance=1
 for i in range(1,301):
+    pen.color(color[i%4])
     pen.forward(i)
     pen.right(91)
-    distance+=1
 turtle.done()