def __init__(self, p1, p2):
        """
        Initialize with two points that are on the line.  Store one of
        the points and the vector between them.
        """
        self.B = p1
        """One point"""
        self.C = p2
        """Other point"""
        self.M = p1 - p2
        """Vector from the stored point to the other point"""
        LineXY.__init__(self, p1, p2)
        """Initialize line attributes"""
dataset/ETHPy150Open rll/lfd/lfd/rapprentice/util.py/LineSeg.__init__/swapped operands of `-`