From bpo-4197:

"""
runpy needs a non-standard PEP-302 extension to set __file__ correctly
in the modules it runs. The pkgutil stuff it uses to find pure Python
modules in the filesystem supports that extension, but zipimport doesn't
(yet).
""" -- Nick Coghlan

I am working on a patch.

I have attached a rough patch implementing the get_filename. I
deliberately copied code from get_source method that finds the filename
inside the zip archive and simply prefixed that with the archive path.

I could not find any detailed discussion of what get_filename is
supposed to do. Pkgutil's get_filename is not documented and not unit-
tested. Google search revealed an old thread at
<http://mail.python.org/pipermail/python-dev/2006-April/063626.html\>,
but it only says

"""

runpy needs a get_filename() method, so it knows what to set __file__
too -
currently its emulation supports that, but it isn't officially part of
the
PEP
302 API.

It sounds like maybe a new PEP is needed to document all the extensions
to
the importer/loader protocols. :(
"""

I don't think a brand new PEP is needed, but an amendment to PEP-302
would be helpful. Nick, do you have any notes on what get_filename
should do in various cases?

My implementation fixes one of the problems in bpo-4197:

$ ./python.exe testmodule.zip 
**********************************************************************
File "testmodule.zip/__main__.py", line ?, in __main__.c
Failed example:
    'line 2'
Expected nothing
Got:
    'line 2'
**********************************************************************
1 items had failures:
   1 of   1 in __main__.c
***Test Failed*** 1 failures.

Note that line number is still reported as '?', but there is no crash.

The spec get_filename is pretty simple:

Return whatever __file__ would be set to if load_module() was called for
this module.

(runpy's problem is that it never actually loads the module in question,
so it never gets the chance to interrogate __file__)

Fixed for 2.7 in r67750.

Will be ported to 2.6, 3.0 and 3.1.

Correction - added as _get_filename() in that revision.

Documenting it and making it public (i.e. removing the underscore) is
still to be done, and will only be done for 2.7/3.1

ZipImporter.get_filename() made public in:
2.7: r69425
3.1: r69426