[Python-Dev] PEP 273: Import Modules from Zip Archives

[James C. Ahlstrom]

Mark Hammond wrote:
> Jim writes:
> 
> > On Windows, the directory is the directory of sys.executable.
> 
> Any chance this can be in sys.prefix, else the directory of sys.executable
> if sys.prefix is empty?
> 
> The reason is for embedding situations - sys.executable may not be a
> reasonable watermark.  We recently had a bug regarding os.popen() on Windows
> for the exact same reason, and a patch was recently checked in that goes to
> great lengths to ensure sys.prefix is always valid even in these embedding
> situations.

Hmmm...., you are right.  Sys.executable doesn't really work for
embedding.

But sys.prefix is obtained from a search of the directory
structure for a "landmark" file, namely os.py.  When the Python
library is in a zip file, it is likely that no landmark files will
be found, and sys.prefix will contain garbage.

Since sys.prefix is searched for, its name is unpredictable.  We
need a known location for python22.zip.

How about using the full path name of pythonXX.dll with the last three
characters changed to "zip"?  This associates the libraries with the DLL,
which is more logical than associating them with the executable.  And the
file name is identical but with "zip" instead of "dll".

Does this work, and solve all embedding problems?

JimA