[Python-Dev] imputil and modulefinder replacements

[James C. Ahlstrom]

Thomas Heller wrote:
> 
> From: "Gordon McMillan" <gmcm@hypernet.com>
> > I would like to propose these (or something quite like them) as
> > replacements for the official versions. The code is quite similar
> > (in fact, the modulefinder code could have been written by
> > subclassing the imputil stuff, but I wrote them the other way
> > 'round).
> >
> It seems noone cares about this. imputil is in the distribution,
> but is it really 'official'?

I care about it.  I am using imputil to implement "jar" files,
zip files of Python libraries.  Greg worked hard to get imputil
into the distribution, and I appreciate his effort.  But I always
wondered if imputil was 'official'.

Users on c.l.p frequently want to ship a stand-alone
Python.  The current answer to this is freeze, but this requires a
C compiler and some work.  A standard jar file implementation would
satisfy this need.  What I am thinking of is documentation which
says something like: "Zip up the Python libraries into pylibs.zip
and put that file in the same directory as python[.exe] and
everything Just Works."

My interest in imputil and ImportManager is to implement jar files,
and neither does this well.  The problem is always how to get the
SpecialImporter.py imported first, and how to hack the imports that
the SpecialImporter.py may need to import.  In iu4.py we see the use
of posix.stat to replace the os module, and the import of only
built-in modules sys, imp, and marshal.  The same is true of imputil.py.

I admit I don't really understand package imports.  But I feel they
are an unsolved problem, because package authors always seem to
write custom ones.

A first-class solution would have these features IMHO:
1) Access to libraries in zip files is implemented in C (I volunteer).
2) All Python library modules can be imported by C code,
   either from directories or zip files.
3) Package import is not implemented in C, it is implemented
   by a Python module which is part of the standard library.
4) If an import of A.B is attempted, and a function
   A.MyCustomImporter() exists, then that is used instead of
   the default.
5) More or better ideas from you all.

Jim Ahlstrom