《树莓派Python编程指南》章节试读

《树莓派Python编程指南》的笔记-第17页 - turtle猫捉老鼠

import turtle
import time
boxsize = 200
caught = False
score = 0
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()
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.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()
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 down, you scored:" + str(score*difficulty))
window.bye()