#!/usr/bin/env python2
# -*- coding: utf-8 -*-

import task01

class DimensionError(Exception):
    pass

class Point:
    pointList = []

    def __init__(self, coord):
        if isinstance(coord, list):
            if task01.is_numeric(coord):
                self.coord = coord
                self.x = coord[0]
                self.y = coord[1]
                if len(coord) == 3:
                    self.z = coord[2]

                self.pointList.append(self.coord)

            else:
                print 'NOT all elements in the list are integers or floats'
        else:
            raise DimensionError('The argument must be a list')

    def add(self, point1, point2):
        point3 = []

        if isinstance(point1, Point) and isinstance(point2, Point):
            point3.append(point1.x + point2.x)
            point3.append(point1.y + point2.y)
            point3.append(point1.z + point2.z)
            return Point(point3)
        else:
            print 'Arguments must be Points'

    def __len__(self):
        return len(self.coord)

    def to_string(self):
        return 'Point coordinates: x: {0} y: {1} z: {2}'.format(self.x, self.y, self.z)

    def __str__(self):
        print self.to_string()