save project

diy1.py

@@ -3,10 +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
 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
 import turtle
+c=turtle.Screen()
+c.bgcolor("black")
 b=turtle.Pen()
 b=turtle.Pen()
-a=1
-for i in range(300):
-    b.forward(a)
-    a=a+1
+b.speed(0)
+colors=["green","red","orange","yellow"]
+for i in range(1,300):
+    b.color(colors[i%4])
+    b.forward(i)
     b.right(91)
     b.right(91)
 turtle.done()
 turtle.done()
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