possiblesmall but complete programs and modules are used as examples to provide realistic use cases the examplesexercise solutionsand the book' errata are available online at www qtrac eu/py book html two sets of examples are provided the standard examples work with any python version--use these if you care about python compatibility the "eg examples work with python or later--use these if you don' need to support python because your programsusers have python or later all of the examples have been tested on windowslinuxand mac os while it is best to use the most recent version of python this is not always possible if your users cannot or will not upgrade every example in this book works with python except where statedand those examples and features that are specific to python are clearly indicated as such although it is possible to use this book to develop software that uses only python for those wanting to produce software that is expected to be in use for many years and that is expected to be compatible with later python releasesit is best to use python as the oldest python version that you support this is partly because python has some very nice new featuresbut mostly because the python developers strongly recommend using python (or laterthe developers have decided that python will be the last python releaseand that there will be no more python releases even if bugs or security problems are discovered insteadthey want all python users to migrate to python (or to later version)which will have the usual bugfix and security maintenance releases that python versions normally have the structure of the book presents eight key pieces of python that are sufficient for writing complete programs it also describes some of the python programming environments that are available and presents two tiny example programsboth built using the eight key pieces of python covered earlier in the through introduce python' procedural programming featuresincluding its basic data types and collection data typesand many useful builtin functions and control structuresas well as very simple text file handling shows how to create custom modules and packages and provides an overview of python' standard library so that you will have good idea of the functionality that python provides out of the box and can avoid reinventing the wheel provides thorough introduction to object-oriented programming with python all of the material on procedural programming that you learned in earlier is still applicablesince object-oriented programming is