用python画圣诞树

import turtlescreen = turtle.Screen()screen.setup(375, 700)circle = turtle.Turtle()circle.shape('circle')circle.color('red')circle.speed('fastest')circle.up()square = turtle.Turtle()square.shape('square')square.color('green')square.speed('fastest')square.up()circle.goto(0, 280)circle.stamp()k = 0for i in range(1, 13): y = 30 * i for j in range(i - k): x = 30 * j square.goto(x, -y + 280) square.stamp() square.goto(-x, -y + 280) square.stamp()if i % 4 == 0: x = 30 * (j + 1) circle.color('red') circle.goto(-x, -y + 280) circle.stamp() circle.goto(x, -y + 280) circle.stamp() k += 3if i % 4 == 3: x = 30 * (j + 1) circle.color('yellow') circle.goto(-x, -y + 280) circle.stamp() circle.goto(x, -y + 280) circle.stamp()square.color('brown')for i in range(13, 17): y = 30 * i for j in range(2): x = 30 * j square.goto(x, -y + 280) square.stamp() square.goto(-x, -y + 280) square.stamp()