import turtle

turtle.speed(0)
# 绘制灯箱
turtle.pensize(5)
turtle.forward(100)
turtle.left(90)
turtle.forward(200)
turtle.left(90)
turtle.forward(100)
turtle.left(90)
turtle.forward(200)
turtle.left(90)

# 绘制第一个灯，红灯
turtle.penup()
turtle.goto(50,200-35)
turtle.pendown()
turtle.dot(50,"red")

# 绘制第二个灯，黄灯
turtle.penup()
turtle.goto(50,200-95)
turtle.pendown()
turtle.dot(50,"yellow")

# 绘制第三个灯，绿灯
turtle.penup()
turtle.goto(50,200-155)
turtle.pendown()
turtle.dot(50,"green")

# 写字
turtle.penup()
turtle.goto(0,-60)
turtle.pendown()
turtle.write("交通灯",font=("Arial",20,"normal"))

turtle.hideturtle()

turtle.done()

继续优化，可以加上倒计时，模拟十字路口，红灯停绿灯行黄灯等一等的效果

import turtle
import time

turtle.speed(0)
turtle.hideturtle()

# 写字
turtle.penup()
turtle.goto(0,-60)
turtle.pendown()
turtle.write("交通灯",font=("Arial",20,"normal"))
turtle.penup()
turtle.goto(0,0)
turtle.pendown()



# 绘制灯箱
turtle.pensize(5)
turtle.forward(100)
turtle.left(90)
turtle.forward(200)
turtle.left(90)
turtle.forward(100)
turtle.left(90)
turtle.forward(200)
turtle.left(90)

# 绘制第一个灯，红灯
turtle.penup()
turtle.goto(50,200-35)
turtle.pendown()
turtle.dot(50,"red")

# 等待5秒，红灯灭
time.sleep(5)
turtle.penup()
turtle.goto(50,200-35)
turtle.pendown()
turtle.dot(50,"white")


# 绘制第二个灯，黄灯
turtle.penup()
turtle.goto(50,200-95)
turtle.pendown()
turtle.dot(50,"yellow")

# 等待2秒，黄灯灭
time.sleep(3)
turtle.penup()
turtle.goto(50,200-95)
turtle.pendown()
turtle.dot(50,"white")


# 绘制第三个灯，绿灯
turtle.penup()
turtle.goto(50,200-155)
turtle.pendown()
turtle.dot(50,"green")



turtle.done()