红绿灯倒计时python

以下是一个红绿灯倒计时的Python程序：

import turtle
import time

# 红绿灯变亮
def hld_d(ys, bj, light):
    light.color(ys, ys)
    light.begin_fill()
    light.circle(bj)
    light.end_fill()

# 红绿灯倒计时
def countdown(t):
    for i in range(t, 0, -1):
        print(i)
        time.sleep(1)

# 初始化窗口和画笔
win = turtle.Screen()
win.title("红绿灯倒计时")
win.bgcolor("black")
pen = turtle.Turtle()
pen.hideturtle()
pen.speed(0)

# 画红灯
pen.penup()
pen.goto(-50, 50)
pen.pendown()
hld_d("red", 50, pen)

# 画黄灯
pen.penup()
pen.goto(-50, 0)
pen.pendown()
ld_d("yellow", 50, pen)

# 画绿灯
pen.penup()
pen.goto(-50, -50)
pen.pendown()
hld_d("green", 50, pen)

# 红绿灯倒计时
while True:
    pen.clear()
    pen.write("3", align="center", font=("Courier", 80, "normal"))
    countdown(3)
    pen.clear()
    hld_d("red", 50, pen)
    pen.write("2", align="center", font=("Courier", 80, "normal"))
    countdown(2)
    pen.clear()
    hld_d("yellow", 50, pen)
    pen.write("1", align="center", font=("Courier", 80, "normal"))
    countdown(1)
    pen.clear()
    hld_d("green", 50, pen)
    pen.write("GO!", align="center", font=("Courier", 80, "normal"))
    time.sleep(2)

turtle.done()

这个程序使用了turtle库来绘制红绿灯，同时使用了time库来实现倒计时功能。程序中定义了两个函数，hld_d用于绘制红绿灯，countdown用于实现倒计时。在主程序中，先绘制了红绿灯，然后进入一个无限循环，每次循环都会清除画布，显示倒计时数字，然后调用countdown函数实现倒计时，最后显示红绿灯的颜色和GO!字样。