用python中turtle画出长方形小火车绕圈，1个车头与4个车身车身要以线相连中的第三个碰撞图

在Python的turtle模块中，可以创建一个长方形小火车模型，并让它绕圈移动。首先，我们需要导入turtle模块，并定义火车的基本元素，比如车头和车身。这里我们以一个车头连接三个车身为例，因为你是说“第三个碰撞”，所以我们将使用循环并在每次迭代中检查是否发生碰撞。

import turtle

# 定义火车部分的函数
def draw_truck_part(x, y):
    turtle.penup()
    turtle.goto(x, y)
    turtle.pendown()
    turtle.forward(50)  # 车身长度
    turtle.right(90)
    turtle.forward(20)  # 车身宽度
    turtle.left(90)
    turtle.forward(50)
    turtle.right(90)
    turtle.forward(20)
    turtle.left(90)
    turtle.forward(10)  # 长方形车头

# 初始化turtle
train_turtle = turtle.Turtle()
train_turtle.shape("turtle")  # 设定turtle形状
train_turtle.color("blue")  # 设置颜色

# 初始位置
start_x = -100
start_y = 0
current_body_num = 0

while True:  # 无限循环让火车绕圈
    train_turtle.penup()
    train_turtle.goto(start_x, start_y)
    train_turtle.pendown()

    # 画车头
    train_turtle.begin_fill()  # 开始填充颜色
    draw_truck_part(train_turtle.xcor(), train_turtle.ycor())
    train_turtle.end_fill()

    # 连接车身
    if current_body_num < 3:
        draw_truck_part(train_turtle.xcor() + 60, train_turtle.ycor())  # 第二个车身
        current_body_num += 1

    # 检测碰撞
    if train_turtle.distance(train_turtle.xcor() + 80, train_turtle.ycor()) <= 20:  # 假设火车宽为20像素，当车头和第三个车身重叠时认为有碰撞
        print("第{}个车身与车头发生碰撞".format(current_body_num))
        break

    # 移动到下一个位置开始新一圈
    train_turtle.right(90)
    train_turtle.forward(200)

    # 旋转turtle方向继续下一段
    train_turtle.right(90)

# 结束程序
turtle.done()