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Revision 3 as of 2004-01-22 10:47:58
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Comment: spurious } deleted, irrelevant #-line deleted
Revision 17 as of 2011-11-10 00:54:07
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Editor: slojuggler
Comment: correction. it's actually sys and not os. will be adding sys correction momentarily.
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## page was renamed from WinShell
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I used [http://tgolden.sc.sabren.com/python/winshell.html winshell] from Tim Golden - a thin wrapper around Windows Shell-Functions. `py2exe` doesn't find imported `win32com.shell` module, and creates invalid distribution without this file. As a result, an application that uses this module may crash at random or miss some features.
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winshell.py starts with For example version 0.2 of [[http://tgolden.sc.sabren.com/python/winshell.html|winshell.py]] from Tim Golden (a thin wrapper around Windows Shell-Functions) starts with:
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py2exe learns, that something is missing:
py2exe reports that something is missing:
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and starting the programm leaves: and starting the program leaves:
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win32com does some magic. There really is no win32com.shell anywhere. `win32com` does some magic in order to allow loading of COM extensions during run time. The actual extensions reside in the `win32comext` directory under site-packages and can't be loaded directly. `win32com`'s [[http://docs.python.org/tutorial/modules.html#packages-in-multiple-directories|__path__]] variable has been changed to point to both `win32com` and `win32comext`. `py2exe`'s modulefinder can't handle runtime changes in `__path__` so we have to tell it about the change beforehand.
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Without shame I browsed [http://cvs.sourceforge.net/viewcvs.py/spambayes/ spambayes source code] and found: Without shame I browsed [[http://spambayes.svn.sourceforge.net/viewvc/spambayes/trunk/spambayes/|Spambayes source code]] and found the code to fix it.
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# ModuleFinder can't handle runtime changes to __path__, but win32com uses them,
# particularly for people who build from sources. Hook this in.
# ...
# ModuleFinder can't handle runtime changes to __path__, but win32com uses them
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    import modulefinder
    import win32com
    for p in win32com.__path__[1:]:
        modulefinder.AddPackagePath("win32com", p)
    for extra in ["win32com.shell","win32com.mapi"]:
        __import__(extra)
        m = sys.modules[extra]
        for p in m.__path__[1:]:
            modulefinder.AddPackagePath(extra, p)
except ImportError:
    # no build path setup, no worries.
    pass
}}}

I just added that in top of my setup.py file:

{{{
#!python
# By default, the installer will be created as dist\Output\setup.exe.

import time
import sys

# ModuleFinder can't handle runtime changes to __path__, but win32com uses them

try:
    import modulefinder
    # py2exe 0.6.4 introduced a replacement modulefinder.
    # This means we have to add package paths there, not to the built-in
    # one. If this new modulefinder gets integrated into Python, then
    # we might be able to revert this some day.
    # if this doesn't work, try import modulefinder
    try:
        import py2exe.mf as modulefinder
    except ImportError:
        import modulefinder
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# ...
# The rest of the setup file.
# ...
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= Impact =

The following products included workaround:
 * Spambayes
 * Mercurial
 * hgsvn

= Ideal proposal =

`py2exe` should detect such well-known problems with well-known modules, and when `win32com.shell` is missing, a workaround should be automatically applied with a corresponding log message:
{{{
The following modules appear to be missing
['Interface', 'intSet', 'mxDateTime.__version__', 'win32com.shell']
Applying automatic workaround for known problem with win32com.shell
}}}

`py2exe` should also fail if required modules are missing unless some `--force` key in effect.

The Problem

py2exe doesn't find imported win32com.shell module, and creates invalid distribution without this file. As a result, an application that uses this module may crash at random or miss some features.

For example version 0.2 of winshell.py from Tim Golden (a thin wrapper around Windows Shell-Functions) starts with:

   1 from win32com import storagecon
   2 from win32com.shell import shell, shellcon

py2exe reports that something is missing:

The following modules appear to be missing
['Interface', 'intSet', 'mxDateTime.__version__', 'win32com.shell']

and starting the program leaves:

Traceback (most recent call last):
  File "xxxxxx.py", line 33, in ?
  File "xxxxxxx.pyo", line 9, in ?
  File "winshell.pyo", line 27, in ?
ImportError: No module named shell

in the log.file.

Explanation

win32com does some magic in order to allow loading of COM extensions during run time. The actual extensions reside in the win32comext directory under site-packages and can't be loaded directly. win32com's __path__ variable has been changed to point to both win32com and win32comext. py2exe's modulefinder can't handle runtime changes in __path__ so we have to tell it about the change beforehand.

Solution

Without shame I browsed Spambayes source code and found the code to fix it.

   1 # ...
   2 # ModuleFinder can't handle runtime changes to __path__, but win32com uses them
   3 try:
   4     # py2exe 0.6.4 introduced a replacement modulefinder.
   5     # This means we have to add package paths there, not to the built-in
   6     # one.  If this new modulefinder gets integrated into Python, then
   7     # we might be able to revert this some day.
   8     # if this doesn't work, try import modulefinder
   9     try:
  10         import py2exe.mf as modulefinder
  11     except ImportError:
  12         import modulefinder
  13     import win32com
  14     for p in win32com.__path__[1:]:
  15         modulefinder.AddPackagePath("win32com", p)
  16     for extra in ["win32com.shell"]: #,"win32com.mapi"
  17         __import__(extra)
  18         m = sys.modules[extra]
  19         for p in m.__path__[1:]:
  20             modulefinder.AddPackagePath(extra, p)
  21 except ImportError:
  22     # no build path setup, no worries.
  23     pass
  24 
  25 from distutils.core import setup
  26 import py2exe
  27 
  28 # ...
  29 # The rest of the setup file.
  30 # ...

And this worked.

Impact

The following products included workaround:

  • Spambayes
  • Mercurial
  • hgsvn

Ideal proposal

py2exe should detect such well-known problems with well-known modules, and when win32com.shell is missing, a workaround should be automatically applied with a corresponding log message:

The following modules appear to be missing
['Interface', 'intSet', 'mxDateTime.__version__', 'win32com.shell']
Applying automatic workaround for known problem with win32com.shell

py2exe should also fail if required modules are missing unless some --force key in effect.

win32com.shell (last edited 2021-08-24 23:35:23 by JimmyRetzlaff)