At 05:02 PM 4/14/2009 +0200, M.-A. Lemburg wrote:
I don't see the emphasis in the PEP on Linux distribution support and the remote possibility of them wanting to combine separate packages back into one package as good argument for adding yet another separate hierarchy of special files which Python scans during imports.
That said, note that most distributions actually take the other route: they try to split up larger packages into smaller ones, so the argument becomes even weaker.
I think you've misunderstood something about the use case. System packaging tools don't like separate packages to contain the *same file*. That means that they *can't* split a larger package up with your proposal, because every one of those packages would have to contain a __pkg__.py -- and thus be in conflict with each other. Either that, or they would have to make a separate system package containing *only* the __pkg__.py, and then make all packages using the namespace depend on it -- which is more work and requires greater co-ordination among packagers. Allowing each system package to contain its own .pkg or .nsp or whatever files, on the other hand, allows each system package to be built independently, without conflict between contents (i.e., having the same file), and without requiring a special pseudo-package to contain the additional file. Also, executing multiple __pkg__.py files means that when multiple system packages are installed to site-packages, only one of them could possibly be executed. (Note that, even though the system packages themselves are not "combined", in practice they will all be installed to the same directory, i.e., site-packages or the platform equivalent thereof.)