New Style classes and inheritance
Objects - Intermediate example from a Well House Consultants training course
More on Objects - Intermediate [link]
Source code: cl_n.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 NEW STYLE CLASSES - the ones that we encourage you
to use as they offer an improved design over old style classes that
make them easier to maintain, and also they remain avaialble in
Python 3.x - which old style classes don't!
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
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