python异常触发及自定义异常类

class Point:
    def __init__(self,x,y):
        self.x = x
        self.y = y

# Define a class to raise Line errors
class LineError(Exception):   #继承自基类Exception
    def __init__(self,ErrorInfo):
        self.errorinfo=ErrorInfo
    def __str__(self):
        return self.errorinfo

class Line:
    def __init__(self,point1,point2):
        self.point1 = point1
        self.point2 = point2
 
        if point1.x==point2.x and point1.y==point2.y:
            raise LineError("Cannot create line")
  
line = Line(Point(1,2),Point(1,2))