"""Short demonstration of a group of classes in Python. There's
a base class called "pubtrans" which defines all types of public
transport that the application supports, and two derived classes
called "bus" and "train" which start off with "pubtrans" as their
basis and are then extended to add extra code and replace the
code which is in the base class as it applied to most (but not
all) piecees of public transport. The demonstration file also
includes a short piece of text code to show how it works, and to
allow you to run it stand alone to validate that it's been installed
correctly and that all dependencies are available.

This example uses OLD STYLE CLASSES. You should avoid using old
style classes in new code (see cl_n.py for the alternative new
style classes), and old style classes are no longer supported from
Python 3.x

A full application (rather than just a demo such as this) should
include documentation strings, and the test harness would be better
written using the doctest or unittest modules"""

class pubtrans:
        def __init__(self,about):
                self.info = about
        def getabout(self):
                return self.info
        def getvehicles(self):
                return 1
class train(pubtrans):
        def __init__(self,about,vehicle_capacity,coaches):
                pubtrans.__init__(self,about)
                self.vc = vehicle_capacity
                self.nc = coaches
        def getcapacity(self):
                return self.vc * self.nc
        def getvehicles(self):
                return self.nc
class bus(pubtrans):
        def __init__(self,about,vehicle_capacity):
                pubtrans.__init__(self,about)
                self.vc = vehicle_capacity
        def getcapacity(self):
                return self.vc
if __name__ == "__main__":
        testgroup = [train("First Great Western cl 150",80,2)]
        testgroup.append(bus("First Avon and Somerset",81))
        testgroup.append(bus("Faresaver",29))
        testgroup.append(train("South West Trains cl 159",75,3))
        format = "%-30s %4d %d"
        tpc = 0
        tvc = 0
        for option in testgroup:
                text = option.getabout()
                pass_count = option.getcapacity()
                veh_count = option.getvehicles()
                tpc += pass_count
                tvc += veh_count
                print format % (text, pass_count, veh_count)
        print format % (" --- TOTAL ---",tpc,tvc)