The Shape Example in Python

Contributed by Rico Schiekel

Here is a slightly improved version of the python example.

IMHO it's more pythonic and more simpler than the original from Monty Stein.

Code for Python

File: shapes2.py

#!/usr/bin/env python
#
# vim:syntax=python:sw=4:ts=4:expandtab


class Shape(object):

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

    def draw(self):
        raise NotImplementedError('draw() not implemented!')

    def move_to(self, newx, newy):
        self.x = newx
        self.y = newy

    def relative_move(self, dx, dy):
        self.x += dx
        self.y += dy


class Rectangle(Shape):

    def __init__(self, x, y, width, height):
        super(Rectangle, self).__init__(x, y)
        self.width = width
        self.height = height

    def draw(self):
        print 'drawing rectangle at (%d,%d) with width %d, height %d' % \
                         (self.x, self.y, self.width, self.height)


class Circle(Shape):

    def __init__(self, x, y, r):
        super(Circle, self).__init__(x, y)
        self.radius = r

    def draw(self):
        print 'drawing circle at (%d,%d) with radius %d' % \
                         (self.x, self.y, self.radius)


if __name__ == '__main__':

    # using shapes polymorphically
    for shape in (Rectangle(10, 20, 5, 6), Circle(15, 25, 8)):
        shape.draw()
        shape.relative_move(100, 100)
        shape.draw()

    # access a rectangle specific function
    rect = Rectangle(0, 0, 15, 15)
    rect.width = 30
    rect.draw()

Output

drawing rectangle at (10,20) with width 5, height 6
drawing rectangle at (110,120) with width 5, height 6
drawing circle at (15,25) with radius 8
drawing circle at (115,125) with radius 8
drawing rectangle at (0,0) with width 30, height 15