#!/usr/bin/python
#?-*-?coding:?UTF-8?-*-

import?random
import?pygame
import?sys
from?pygame.locals?import?*
?
Snakespeed?=?17
Window_Width?=?800
Window_Height?=?500
Cell_Size?=?20??#?Width?and?height?of?the?cells
#?Ensuring?that?the?cells?fit?perfectly?in?the?window.?eg?if?cell?size?was
#?10?????and?window?width?or?windowheight?were?15?only?1.5?cells?would
#?fit.
assert?Window_Width?%?Cell_Size?==?0?“Window?width?must?be?a?multiple?of?cell?size.“
#?Ensuring?that?only?whole?integer?number?of?cells?fit?perfectly?in?the?window.
assert?Window_Height?%?Cell_Size?==?0?“Window?height?must?be?a?multiple?of?cell?size.“
Cell_W?=?int（Window_Width?/?Cell_Size）??#?Cell?Width
Cell_H?=?int（Window_Height?/?Cell_Size）??#?Cellc?Height
?
?
White?=?（255?255?255）
Black?=?（0?0?0）