小程序6：贪吃蛇(字典加函数)

代码实现：

# -*- coding: utf-8 -*-
# !/user/bin/env python
x = 0
y = 0
def up(): # w
    global y
    y+=1
def down(): # s
    global y
    y-=1
def right(): #a
    global x
    x+=1
def left(): #d
    global x
    x-=1

mydict = {'w':up , 's':down , 'a':right , 'd':left}
while True:
    action = raw_input()
    try:
        mydict[action]() # 函数加括号就是调用
    except KeyError:
        print('输入错了')
        pass