Improved Python Koans

Improved Python Koans is based on gregmalcolm's python koans project at https://github.com/gregmalcolm/python_koans but add more python koans and support optional koans.

Python Koans is a port of Edgecase's "Ruby Koans" which can be found at http://rubykoans.com/.

Python Koans is an interactive tutorial for learning the Python programming language by making tests pass.

Most tests are fixed by filling the missing parts of assert functions. Eg:

self.assertEqual(__, 1+2)

which can be fixed by replacing the __ part with the appropriate code:

self.assertEqual(3, 1+2)

Occasionally you will encounter some failing tests that are already filled out. In these cases you will need to finish implementing some code to progress. For example, there is an exercise for writing some code that will tell you if a triangle is equilateral, isosceles or scalene.

As well as being a great way to learn some Python, it is also a good way to get a taste of Test Driven Development (TDD).

Downloading Python Koans

Python Koans is available through git on Github:

http://github.com/polarization/python_koans

Either site will allow you to download the source as a zip/gz/bz2.

Installing Python Koans

Aside from downloading or checking out the latest version of Python Koans, you need to install the Python interpreter.

At this time of writing, there are two versions of the Python Koans:

• one for use with Python 2.7 (earlier versions are no longer supported)
• one for Python 3.3+

You should be able to work with newer Python versions, but older ones will likely give you problems.

You can download Python from here:

http://www.python.org/download

After installing Python make sure the folder containing the python executable is in the system path. In other words, you need to be able to run Python from a command console. With Python 2 it will be called python or python.exe depending on the operating system. For Python 3 it will either be python3 or for windows it will be python.exe.

If you have problems, this may help:

http://www.python.org/about/gettingstarted

Windows users may also want to update the line in the batch file run.bat to set the python path:

SET PYTHON_PATH=C:\Python27

Getting Started

Jake Hebbert has created a couple of screencasts available here:

http://www.youtube.com/watch?v=e2WXgXEjbHY&list=PL5Up_u-XkWgNcunP_UrTJG_3EXgbK2BQJ&index=1

Or if you prefer to read:

From a *nix terminal or windows command prompt go to the python koans\python_VERSION folder and run:

python contemplate_koans.py

or:

python3 contemplate_koans.py

If you would like to run optional koans, python koans\python_VERSION folder and run:

python contemplate_optional_koans.py

or:

python contemplate_optional_koans.py

Apparently a test failed:

AssertionError: False is not True

It also tells me exactly where the problem in, its an assert on line 12 of .\koans\about_asserts.py. This one is easy, just change False to True to make the test pass.

Getting the Most From the Koans

Quoting the Ruby Koans instructions:

"In test-driven development the mantra has always been, red, green,
refactor. Write a failing test and run it (red), make the test pass
(green), then refactor it (that is look at the code and see if you
can make it any better). In this case you will need to run the koan
and see it fail (red), make the test pass (green), then take a
moment and reflect upon the test to see what it is teaching you
and improve the code to better communicate its intent (refactor)."

Content

Content for Python 3 is a little different to the Python 2 flavor due to big changes between the two different versions of the language. For example, in the Python 2 variant the differences between old and new style classes are covered. This loses relevance in in the Python 3 version, but there are some extra tests covering new functionality.

Acknowledgments

Thanks go to gregmalcolm for the original Python Koans that the Improved Python Koans is based on! Thanks go to Jim Weirich and Joe O'Brien for the original Ruby Koans that the Python Koans is based on! Also the Ruby Koans in turn borrows from Metakoans so thanks also go to Ara Howard for that!

Also thanks to everyone who has contributed to Python Koans! I got a great headstart by taking over a code base initiated by the combined Mikes of FPIP. So here's a little plug for their very cool Python podcast:

http://frompythonimportpodcast.com/