将值分配给for循环中的zip时，为什么这不起作用？

    x_coord = [23, 53, 2, -12, 95, 103, 14, -5]
    y_coord = [677, 233, 405, 433, 905, 376, 432, 445]
    z_coord = [4, 16, -6, -42, 3, -6, 23, -1]
    labels = ["F", "J", "A", "Q", "Y", "B", "W", "X"]

    points = []

    for x, y, z, label in zip(x_coord, y_coord, z_coord, labels):
    #    points.append(label + ":" + str(x) + "," + str(y) + "," + str(z)) #idea 1. working
        for point in points: #idea 2. not working. 
            point = label + ":" + str(x) + "," + str(y) + "," + str(z)

    for point in points:
        print(point)

我正在学习python中的zip方法。我需要将这些坐标与某种格式的标签结合起来。我想出了2个主意，但是第二个主意不起作用。我一直在猜测这一点，但我不知道为什么它不起作用。我使用了print方法来检查for循环中发生了什么，但没有显示任何内容。请帮助我解决这个问题。