[Distutils] distutils and the development process

[Greg Ward]

On 25 February 2000, est@hyperreal.org said:
> I have two major continued problems even when I do, "export
> PYTHONPATH=build/lib:build/platlib".
> 
> 1) When developing in the top-level directory of a distribution, the
> current directory still comes first in sys.path, so python still
> thinks the package source directory (with its __init__.py) is where
> the package lives.

Yeah, I see the problem -- putting test scripts in a test directory is
not a full solution; what about interactive sessions?  And while it's
good practice to put test scripts in a test directory, I don't want to
*force* people to do that.

> 2) Even when executing an example script in a sub-directory, python
> gets the idea that the package is in build/lib and doesn't find it's
> extension submodules.  If I copy those over to the build/lib
> subdirectory they are found.

Oops.  This is handled properly on installation, since build/lib and
build/platlib are merged at that point.  I've been wondering for a while
why I decided always to build pure Python modules to build/lib, and
extensions to build/platlib.  You have discovered a very good reason
*not* to do so: it breaks the idea of the build tree as a
pseudo-installation for testing purposes.

> If I think of good strategies for dealing with these problems, I'll
> post them.  In the meantime, it's back to Makefiles for me. :)

I see a couple of solutions: first, put all modules in either build/lib
or build/platlib, i.e. do the merge at build-time rather than
install-time.  Second, have some sort of "build in-place" option that
lets developers, well, build in-place.  That is, .py files in the source
tree wouldn't be touched (they're already in-place!), and extension
modules would be put into the source tree.  (I still favour putting
compiler turds in build/temp.plat -- anyone foresee problems with that?)

I'm still struggling with the Right Way to install modules, so I won't
be able to work on fixing the build stuff right away.  Keep bugging me
though!

        Greg
-- 
Greg Ward - Linux bigot                                 gward@python.net
http://starship.python.net/~gward/
A man wrapped up in himself makes a very small package.