Python 小游戏，猫和老鼠

[MARKmj]

'''
猫和老鼠游戏：
实验功能：
    用方向键控制老鼠，使其保持在猫的前方。
    由计算机控制猫
    保持时间越长，得分越高
'''
import turtle
import time

boxsize = 300
caught = False
score = 0

# functions that are called on keypresses
def up():
    mouse.forward(10)
    checkbound()

def left():
    mouse.left(45)

def right():
    mouse.right(45)

def back():
    mouse.backward(10)
    checkbound()

def quitTurtles():
    window.bye()

# stop the mouse from leaving the square set by box size

def checkbound():
    global boxsize
    if mouse.xcor() > boxsize:
        mouse.goto(boxsize,mouse.ycor)
    if mouse.xcor() < -boxsize:
        mouse.goto(-boxsize,mouse.ycor)
    if mouse.ycor() > boxsize:
        mouse.goto(mouse.xcor,boxsize)
    if mouse.ycor() < -boxsize:
        mouse.goto(mouse.xcor,-boxsize)

# set up screen
window = turtle.Screen()
mouse = turtle.Turtle()
cat = turtle.Turtle()
mouse.penup()
mouse.penup()
mouse.goto(100,100)

# add key listeners
window.onkeypress(up,"Up")
window.onkeypress(left,"Left")
window.onkeypress(right,"Right")
window.onkeypress(back,"Down")
window.onkeypress(quitTurtles,"Escape")

difficulty = window.numinput('Difficulty','Enter a difficulty from easy (1),for hard (5)',minval = 1,maxval = 5)

window.listen()

# main loop
# note how it change with difficulty
while not caught:
    cat.setheading(cat.towards(mouse))
    cat.forward(8+difficulty)
    score = score + 1
    if cat.distance(mouse) < 5:
        caught = True
    time.sleep(0.2 - (0.01*difficulty))
window.textinput('Game Over','Well done.You scored:'+ str(score*difficulty))
window.bye()