Message11667

Technically CPython is the "reference implementation" of Python. This title rather assumes there is a formal specification. The nearest thing we have is the manual (meaning the Language Reference and Library Reference). 

CPython makes a lot of choices the documents don't specify. E.g. what are the allowable argument types in str.split, or unicode.split?

There are things in the manual explicitly marked as details of CPython not all implementations have to reproduce, for example here: https://docs.python.org/3/reference/datamodel.html#objects-values-and-types . It is also possible to have forgotten to insert such a note when it is deserved.

In the interests of a quiet life and painless re-use, Jython reproduces the behaviour of CPython if it possibly can, and avoids going beyond in any major ways, except for things we think fundamental to a JVM implementation (like memory management).

So in this case, if wall-clock time is acceptable for CPython on Windows, and CPU time on Unix, either might be acceptable for Jython, or something natural to the Java platform might be better.