Old Style classes and inheritance
Objects - Intermediate example from a Well House Consultants training course
More on Objects - Intermediate [link]
Source code: cl_o.py Module: Y112
"""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
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"""
self.info = about
self.vc = vehicle_capacity
self.nc = coaches
return self.vc * self.nc
self.vc = vehicle_capacity
if __name__ == "__main__":
testgroup = [train("First Great Western cl 150",80,2)]
testgroup.append(bus("First Avon and Somerset",81))
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)
Learn about this subject
This module and example are covered on the following public courses:
* Learning to program in Python
* Python Programming
* Intermediate Python
Also available on on site courses for larger groups
Books covering this topic
Yes. We have over 700 books in our library. Books covering Python are listed here and when you've selected a relevant book we'll link you on to Amazon to order.
This example comes from our "Objects - Intermediate" training module. You'll find a description of the topic and some other closely related examples on the "Objects - Intermediate" module index page.
Full description of the source code
You can learn more about this example on the training courses listed on this page, on which you'll be given a full set of training notes.
Many other training modules are available for download (for limited use) from our download centre under an Open Training Notes License.
• Our Solutions centre provides a number of longer technical articles.
• Our Opentalk forum archive provides a question and answer centre.
• The Horse's mouth provides a daily tip or thought.
• Further resources are available via the resources centre.
• All of these resources can be searched through through our search engine
• And there's a global index here.
Web site author
This web site is written and maintained by Well House Consultants.
Purpose of this website
This is a sample program, class demonstration or answer from a training course. It's main purpose is to provide an after-course service to customers who have attended our public private or on site courses, but the examples are made generally available under conditions described below.
Conditions of use
Past attendees on our training courses are welcome to use individual examples in the course of their programming, but must check the examples they use to ensure that they are suitable for their job. Remember that some of our examples show you how not to do things - check in your notes. Well House Consultants take no responsibility for the suitability of these example programs to customer's needs.
This program is copyright Well House Consultants Ltd. You are forbidden from using it for running your own training courses without our prior written permission. See our page on courseware provision for more details.
Any of our images within this code may NOT be reused on a public URL without our prior permission. For Bona Fide personal use, we will often grant you permission provided that you provide a link back. Commercial use on a website will incur a license fee for each image used - details on request.
PH: 01144 1225 708225 • EMAIL: firstname.lastname@example.org • WEB: http://www.wellho.net • SKYPE: wellho
PAGE: http://www.wellho.net/resources/ex.php • PAGE BUILT: Sun Oct 11 14:50:09 2020 • BUILD SYSTEM: JelliaJamb