#!/usr/bin/env python

"""

simple_classes.py

demonstrating the basics of a class

"""

import math

## create a point class

class Point(object):

def __init__(self, x, y):

self.x = x

self.y = y

## create an instance of that class

p = Point(3,4)

## access the attributes

print "p.x is:", p.x

print "p.y is:", p.y

class Point2(object):

size = 4

color= "red"

def __init__(self, x, y):

self.x = x

self.y = y

p2 = Point2(4,5)

print p2.size

print p2.color

class Point3(object):

size = 4

color= "red"

def __init__(self, x, y):

self.x = x

self.y = y

def get_color(self):

return self.color

p3 = Point3(4,5)

print p3.size

print p3.get_color()

class Circle(object):

color = "red"

styles = ['dashed']

def __init__(self, diameter):

self.diameter = diameter

def grow(self, factor=2):

"""

grows the circle's diameter

:param factor=2: factor by which to grow the circle

"""

self.diameter = self.diameter * factor

def add_style(self, style):

self.styles.append(style)

def get_area(self):

return math.pi * self.diameter / 2.0

class NewCircle(Circle):

color = "blue"

def grow(self, factor=2):

"""grows the area by factor..."""

self.diameter = self.diameter * math.sqrt(2)

nc = NewCircle

print nc.color

class CircleR(Circle):

def __init__(self, radius):

diameter = radius*2

Circle.__init__(self, diameter)

class CircleR2(Circle):

def __init__(self, radius):

self.radius = radius

def get_area(self):

return Circle.get_area(self, self.radius*2)