# создаем класс Ломаная
class Poly_chain:
    """ Самостоятельный Poly_chain class """
    #_Vertices={}
    def __init__(self, *_Points,_Points_names=None):
        self._Vertices = {}
        _points_number=len(_Points)
        if _points_number>0:
            if type(_Points_names)!=type((1, 2)) and type(_Points_names) != type([]):
                counter=1
                for _P in _Points:
                    self._Vertices['A_'+str(counter)]=_P
                    counter+=1
            else:
                for counter in range(_points_number):
                    self._Vertices[_Points_names[counter]]=_Points[counter]

    def vertices(self):
        return self._Vertices.values()
    def vertices_names(self):
        return self._Vertices.keys()
    def named_vertices(self):
        return self._Vertices
    def plot(self,color='blue'):
        plt.plot([P.x for P in list(self._Vertices.values())],[P.y for P in list(self._Vertices.values())], color)

    def plot_annotated(self,color='blue'):
        self.plot(color)
        for V_name in (self.named_vertices().keys()):
            chain_point=self.named_vertices()[V_name]
            plt.annotate('$'+V_name+'$',xy=(chain_point.x, chain_point.y),xytext=(0, 5), textcoords='offset points' )


class Triangle(Poly_chain):
    """ Потомок Poly_chain class """
    def __init__(self, *_Points,_Points_names=None):
        # Необходимо вызвать метод инициализации родителя.
        # В Python 3.x это делается при помощи функции super()
        super().__init__(*_Points,_Points_names=_Points_names)
        return None
    def plot(self,_color='blue'):
        names = list(self.vertices_names())
        _V=list(self.vertices())+[self._Vertices[names[0]]]
        plt.plot([P.x for P in _V],[P.y for P in _V])
        return None
    def plot_annotate(self, _color='blue'):
        self.plot(color)
        for V_name in (self.named_vertices().keys()):
            chain_point=self.named_vertices()[V_name]
            plt.annotate('$'+V_name+'$',xy=(chain_point.x, chain_point.y),xytext=(0, 5), textcoords='offset points' )

    def display(self):
        name = ""
        for i in list(self.vertices_names()):
            name+=i
        print('Треугольник %s' % (name))
        return None