[Python-Dev] Packaging and binary distributions

Mon Nov 7 10:26:09 CET 2011

Martin v. Löwis <martin <at> v.loewis.de> writes:
>> Again, that's a bdist_msi implementation issue. It could generate custom
> actions that run the "proper" setup.cfg hooks (I presume - I have no
> idea what a setup.cfg hook actually is).
>
I know that custom hooks are quite powerful, but my comment was about having
the functionality in Python. Here's an example of a working hooks.py:
import os
import sys
if os.name == 'nt':
 def get_personal_path():
 from ctypes import (wintypes, windll, create_unicode_buffer, WinError,
 c_int, HRESULT)
 from ctypes.wintypes import HWND, HANDLE, DWORD, LPWSTR, MAX_PATH
 CSIDL_PERSONAL = 5
 # We use an older API to remain XP-compatible.
 SHGetFolderPath = windll.shell32.SHGetFolderPathW
 SHGetFolderPath.argtypes = [HWND, c_int, HANDLE, DWORD, LPWSTR]
 SHGetFolderPath.restype = DWORD
 path = create_unicode_buffer(MAX_PATH)
 hr = SHGetFolderPath(0, CSIDL_PERSONAL, 0, 0, path)
 if hr != 0:
 raise WinError()
 return path.value
 path = get_personal_path()
 del get_personal_path

 # Assume ~\Documents\WindowsPowerShell\Modules is in $PSModulePath,
 # which should be true in a default installation of PowerShell 2.0.
 psroot = os.path.join(path, 'WindowsPowerShell')
 psmodules = os.path.join(psroot, 'Modules')
 psscripts = os.path.join(psroot, 'Scripts')
def setup(config):
 files = config['files']
 if os.name != 'nt':
 files_to_add = 'virtualenvwrapper.sh = {scripts}'
 else:
 files_to_add = ('winfiles/ *.ps* = '
 '{psmodules}/virtualenvwrapper\n'
 'winfiles/ vew_profile.ps1 = {psscripts}')
 if 'resources' not in files:
 files['resources'] = files_to_add
 else:
 files['resources'] += '\n%s' % files_to_add
def pre_install_data(cmd):
 if os.name == 'nt':
 cmd.categories['psmodules'] = psmodules
 cmd.categories['psscripts'] = psscripts
 cmd.categories['psroot'] = psroot
which works with the following setup.cfg:
[global]
setup_hooks = hooks.setup
[install_data]
pre-hook.win32 = hooks.pre_install_data
categories =
 cat1 = /path/one
# comment 
 cat2 = /path/two
#[install_dist]
#post-hook.win32 = hooks.post_install_dist
[metadata]
name = nemo
version = 0.1
summary = New Environments Made, Obviously
description = A tool to manage virtual environments
download_url = UNKNOWN
home_page = https://bitbucket.org/vinay.sajip/nemo
author = Vinay Sajip
author_email = vinay_sajip at yahoo.co.uk
license = BSD
classifier = Development Status :: 3 - Alpha
 Programming Language :: Python :: 3
 Operating System :: OS Independent
 Intended Audience :: System Administrators
 Intended Audience :: Developers
 License :: OSI Approved :: BSD License
requires_python = >= 3.3
[files]
packages = nemo
 virtualenvwrapper
scripts =
 nemo = nemo.main
extra_files =
 hooks.py
 winfiles/*
# Additional esources are added in hooks based on platform
resources =
 nemo/scripts/** = {purelib}
I'm curious to know how this level of flexibility can be achieved with the
MSI format: I know one can code the equivalent logic in C (for example) in
a custom action, but don't know how you can keep the logic in Python.
Regards,
Vinay Sajip