【Python基础】1.4.5 Turtle实例——用Python实现时钟显示

语言：Python
IDE：Python.IDE

1. 编写时钟程序，要求根据时间动态更新
   

2. 代码思路
   需求：5个Turtle对象， 1个绘制外表盘+3个模拟表上针+1个输出文字
   Step1：建立Turtle对象并初始化
   Step2：静态表盘绘制
   Step3：根据时钟更新表针位置与时间信息
   基本库：Turtle、datetime

3. 代码段

from turtle import *
from datetime import *

def Skip(step):
    penup()
    forward(step)
    pendown()

def mkHand(name, length):
    #注册Turtle形状，建立表针Turtle
    reset()
    Skip(-length*0.1)
    begin_poly()
    forward(length*1.1)
    end_poly()
    handForm = get_poly()
    #注册Turtle形状命令register_shape(name,shape=None)
    register_shape(name, handForm)

def Init():
    global secHand, minHand, hurHand, printer
    mode("logo")# 重置Turtle指向北
    #建立三个表针Turtle并初始化
    #第二个参数为长度
    mkHand("secHand", 125)
    mkHand("minHand",  130)
    mkHand("hurHand", 90)
    secHand = Turtle()
    secHand.shape("secHand")
    minHand = Turtle()
    minHand.shape("minHand")
    hurHand = Turtle()
    hurHand.shape("hurHand")
    for hand in secHand, minHand, hurHand:
        hand.shapesize(1, 1, 3)
        hand.speed(0)
    #建立输出文字Turtle
    printer = Turtle()
    printer.hideturtle()
    printer.penup()

def SetupClock(radius):
    #建立表的外框
    reset()
    pensize(7)
    for i in range(60):
        Skip(radius)
        if i % 5 == 0:
            forward(20)
            Skip(-radius-20)
        else:
            dot(5)
            Skip(-radius)
        right(6)

def Week(t):    
    week = ["星期一", "星期二", "星期三",
            "星期四", "星期五", "星期六", "星期日"]
    return week[t.weekday()]

def Date(t):
    y = t.year
    m = t.month
    d = t.day
    return "%s %d %d" % (y, m, d)

def Tick():
    #绘制表针的动态显示
    #当前时间
    t = datetime.today()
    second = t.second + t.microsecond*0.000001
    minute = t.minute + second/60.0
    hour = t.hour + minute/60.0
    secHand.setheading(6*second)
    minHand.setheading(6*minute)
    hurHand.setheading(30*hour)

     #介入Tracer函数以控制刷新速度
    tracer(False)  
    printer.forward(65)
    printer.write(Week(t), align="center",
                  font=("Courier", 14, "bold"))
    printer.back(130)
    printer.write(Date(t), align="center",
                  font=("Courier", 14, "bold"))
    printer.home()
    tracer(True)

    ontimer(Tick, 100)#100ms后继续调用tick

def main():
    tracer(False)
    Init()
    SetupClock(160)
    tracer(True)
    Tick()
    mainloop()

if __name__ == "__main__":       
    main()