Message1409

First of all I have to say I'm such a newbie with Jython internals that what I write here may not be 100% true. Anyway, I've understood that javapath acts as any other platform specific os.path implementation -- in Jython's case the platform is not the actual OS but the JVM. I believe the line in javaos that says "os.path is one of the modules posixpath, ntpath, macpath, or dospath" is just copied from CPython version and not updated accordingly. 

The problem with Jython is that even though the JVM is the platform people using Jython expect it works correctly (i.e. similarly as CPython) in any particular OS. The idea to use OS specific path modules is of course one possibility to solve this problem but unfortunately using CPython modules without modifications is probably not an option. CPython modules like posixpath and ntpath are heavily dependent on os.stat which, due to JVM limitations, only sets file size and mtime correctly in Jython. Thus the current approach is probably the simplest because java.io.File provides most of the functionality needed to implement CPython compatible os.path. There are cases where Java and CPython implementations differ (e.g. os.path.abspath normalizes the returned path but java.io.File.getAbsolutePath doesn't) but in my opinion they can be handled inside javapath.