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For 2021 - online Python 3 training - see ((here)).

Our plans were to retire in summer 2020 and see the world, but Coronavirus has lead us into a lot of lockdown programming in Python 3 and PHP 7.
We can now offer tailored online training - small groups, real tutors - works really well for groups of 4 to 14 delegates. Anywhere in the world; course language English.

Please ask about private 'maintenance' training for Python 2, Tcl, Perl, PHP, Lua, etc.
Python base and inherited classes, test harness and unit testing - new examples

From a recent Python course ... a new series of examples on writing, testing and using classes. The customer is using Python 2.6 and 2.7, so the code is written with what we call "new style classes" where everything eventually inherits from a base class os object - with that eventual inheritance expected to become implicit when the code is moved to Python 3.

The class definition itself is [here] - a class of "transport" to be the base for various types of transport which are all defined below within the same source file, and it also includes a very simple test harness.

Testing of code is critical, and I used this newly written class during the course as my basis for writing tests and showing off the unittest modules in simple examples - [here] for "Hello testing world" giving very simple results:

  munchkin: grahamellis$ python utdemo
  ...
  ----------------------------------------------------------------------
  Ran 3 tests in 0.000s
  
  OK
  munchkin: grahamellis$


and [here] for a test set which produces a far more verbose output, and also demonstrates how errors are flagged:

  munchkin: grahamellis$ python utd2
  test_001 (__main__.Mytests) ... ok
  test_002 (__main__.Mytests) ... ok
  test_003 (__main__.Mytests) ... ok
  test_004 (__main__.Mytests) ... ok
  test_005 (__main__.Mytests) ... ERROR
  
  ======================================================================
  ERROR: test_005 (__main__.Mytests)
  ----------------------------------------------------------------------
  Traceback (most recent call last):
    File "utd2", line 25, in test_005
      c = self.example.getstandees()
  AttributeError: 'train' object has no attribute 'getstandees'
  
  ----------------------------------------------------------------------
  Ran 5 tests in 0.001s
  
  FAILED (errors=1)
  munchkin: grahamellis$


Following on from our tests, there are further examples - application code snippets that use the transport classes [here] and [here], with that latter example showing how a data file can be loaded into a list of objects through a factory method. Sample data file [here].

What's missing from these examples? Documentation Strings! ... simply because the examples were written dynamically in front of delegates during the course, with time being limited, and with a desire for the whole example to fit onto a single projection screen. The documentation was there, in my verbal comments and descriptions, as the course ran - if you can think of it like that.
(written 2014-12-07)

 
Associated topics are indexed as below, or enter http://melksh.am/nnnn for individual articles
Y112 - Python - Objects - Intermediate
  [296] Using a Python dictionary as a holder of object attributes - (2005-04-30)
  [383] Overloading of operators on standard objects in Python - (2005-07-19)
  [477] Class, static and unbound variables - (2005-10-25)
  [656] Think about your design even if you don't use full UML - (2006-03-24)
  [831] Comparison of Object Oriented Philosophy - Python, Java, C++, Perl - (2006-08-13)
  [903] Pieces of Python - (2006-10-23)
  [964] Practical polymorphism in action - (2006-12-04)
  [1146] __new__ v __init__ - python constructor alternatives? - (2007-04-14)
  [1217] What are factory and singleton classes? - (2007-06-04)
  [1517] Python - formatting objects - (2008-01-24)
  [1644] Using a utility method to construct objects of different types - Python - (2008-05-17)
  [1661] Equality, sameness and identity - Python - (2008-05-31)
  [1819] Calling base class constructors - (2008-10-03)
  [2368] Python - fresh examples of all the fundamentals - (2009-08-20)
  [2409] TypeError: super() argument 1 must be type, not classobj (Python) - (2009-09-18)
  [2485] How do I set up a constant in Python? - (2009-10-31)
  [2693] Methods that run on classes (static methods) in Python - (2010-03-25)
  [2717] The Multiple Inheritance Conundrum, interfaces and mixins - (2010-04-11)
  [2720] Multiple inheritance in Python - complete working example - (2010-04-14)
  [2722] Mixins example in Python - (2010-04-14)
  [2764] Python decorators - your own, staticmethod and classmethod - (2010-05-14)
  [2785] The Light bulb moment when people see how Object Orientation works in real use - (2010-05-28)
  [2889] Should Python classes each be in their own file? - (2010-07-27)
  [2905] Defining static methods in Python - (2010-08-05)
  [2994] Python - some common questions answered in code examples - (2010-10-10)
  [3002] A list of special method and attribute names in Python - (2010-10-17)
  [3442] A demonstration of how many Python facilities work together - (2011-09-16)
  [3472] Static variables in functions - and better ways using objects - (2011-10-10)
  [3524] Metaclasses (Python) and Metatables (Lua) - (2011-11-17)
  [3796] Backquote, backtic, str and repr in Python - conversion object to string - (2012-07-05)
  [3887] Inheritance, Composition and Associated objects - when to use which - Python example - (2012-10-10)
  [4028] Really Simple Class and Inheritance example in Python - (2013-03-04)
  [4094] Python Properties - how and why - (2013-05-18)
  [4356] Object factories in C++, Python, PHP and Perl - (2014-12-19)
  [4366] Changing what operators do on objects - a comparison across different programming languages - (2014-12-26)
  [4410] A good example of recursion - a real use in Python - (2015-02-01)
  [4449] Spike solution, refactoring into encapsulated object methods - good design practise - (2015-03-05)
  [4450] Deciding whether to use parameters, conditional statements or subclasses - (2015-03-05)
  [4541] Setting up and tearing down with the Python with keyword - (2015-10-16)
  [4649] Object and Static methods - what is the difference; example in Python 3 - (2016-02-17)
  [4717] with in Python - examples of use, and of defining your own context - (2016-11-02)
  [4718] Defining an object that is a modified standard type in Python - (2016-11-02)
  [4719] Nesting decorators - (2016-11-02)

Y212 - Python - Code testing, patterns, profiles and optimisation.
  [235] Preparation for a day's work - (2005-03-04)
  [1140] Python GTK - Widget, Packing, Event and Feedback example - (2007-04-09)
  [1148] Python decorators - wrapping a method call in extra code - (2007-04-15)
  [1555] Advanced Python, Perl, PHP and Tcl training courses / classes - (2008-02-25)
  [2123] Using Python with OpenOffice - (2009-04-09)
  [2616] Defining a static method - Java, Python and Ruby - (2010-02-01)
  [3441] Pressing ^C in a Python program. Also Progress Bar. - (2011-09-15)
  [3464] Passing optional and named parameters to python methods - (2011-10-04)
  [3478] Testing your Python classes with the unittest package - how to - (2011-10-14)
  [3658] Using Make for a distribution - (2012-03-17)
  [4090] Test Driven Development in Python - Customer Comes First - (2013-05-16)
  [4326] Learning to program - comments, documentation and test code - (2014-11-22)
  [4446] Combining tests into suites, and suites into bigger suites - Python and unittest - (2015-03-01)
  [4470] Testing in Python 3 - unittest, doctest and __name__ == __main__ too. - (2015-04-21)
  [4538] Flask and unittest - hello web app test world - (2015-10-15)
  [4540] Unittest of a Flask application including forms - (2015-10-15)
  [4542] The principle of mocking - and the Python Mock package - (2015-10-17)
  [4617] Pytest - starting example - (2016-01-07)
  [4618] Pytest - second example beyond hello world - (2016-01-08)
  [4716] Profiling your Python program - (2016-11-01)


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Incrementing a variable in Java - Pre and Post Increment
Some other Articles
Taking my life in my hands in Swansea
Arrays in Java - an introduction for newcomers
A behaviour driven example of writing a Java program
Incrementing a variable in Java - Pre and Post Increment
Python base and inherited classes, test harness and unit testing - new examples
Politics and the railway the connects Wiltshire
My first official measure - Passenger Entrys and Exits - revisited 9 years later
Segmentation Fault, Segmentation Violation, Bus Error, Stack Smashing
Command line and file handling in C
Simple C structs - building up to full, dynamic example
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This is a page archived from The Horse's Mouth at http://www.wellho.net/horse/ - the diary and writings of Graham Ellis. Every attempt was made to provide current information at the time the page was written, but things do move forward in our business - new software releases, price changes, new techniques. Please check back via our main site for current courses, prices, versions, etc - any mention of a price in "The Horse's Mouth" cannot be taken as an offer to supply at that price.

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