from geometry_msgs.msg import Quaternion中的Quaternion类的格式

Quaternion类的格式如下：

class Quaternion:
    """
    This represents an orientation in free space in quaternion form.

    float64 x, y, z, w
    """
    __slots__ = ['x', 'y', 'z', 'w']

    def __init__(self, x=0.0, y=0.0, z=0.0, w=1.0):
        """
        Constructor.

        :param x: The x component of the quaternion.
        :type x: float
        :param y: The y component of the quaternion.
        :type y: float
        :param z: The z component of the quaternion.
        :type z: float
        :param w: The w component of the quaternion.
        :type w: float
        """
        self.x = x
        self.y = y
        self.z = z
        self.w = w

Quaternion类包含四个成员变量x、y、z、w，分别表示四元数的四个分量。构造函数可以传入四个参数来初始化四元数的分量，默认值为(0,0,0,1)。