Update and rename task9.py to colorful_snake.py

Author: aleena-zahra

task9.py renamed to colorful_snake.py

@@ -1,6 +1,7 @@
 import turtle
 from turtle import Screen
 import random
+
 screen = Screen()
 speed=10
 
@@ -9,6 +10,8 @@
 snake.width(width=5)
 snake.hideturtle()
 snake.color(random.choice(colors))
+#functions that define movement in 4 directions
+#color changes each time snake moves
 def go_up():
     global snake
     snake.color(random.choice(colors))
@@ -31,11 +34,11 @@ def go_left():
     x=snake.xcor()
     snake.setx(x-speed) 
 
-
+#functions to respond to user pressing arrow keys
 screen.listen()
 screen.onkeypress(go_up,"Up")
 screen.onkeypress(go_down,"Down")
 screen.onkeypress(go_right,"Right")
 screen.onkeypress(go_left,"Left")
 
-turtle.done()
+turtle.done()