'proper' & reliable way to get all installed windows programs in Python?

Question

I've seen numerous ways of retrieving installed programs on WinXP+ in python. What is the proper and most robust way of doing this?

Currently I'm accessing HKLM\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Uninstall and reading each of the keys from there to get a list. (I've been told this isn't the proper way of doing things) I've seen examples of using WMI/Win32com to do this as well but have seen comments along with those implementations that WMI might be turned off on certain machines and that it's not a very reliable solution.

Is there a method which is both proper, and reliable to get a list of installed programs? None of the WMI examples I've seen have worked on this machine (hence my reluctance to use it, I'm only running WinFLP; which is a stripped vers of XP.)

I seem to have also found the TechNet article which my searches have turned up which is provided to a similar answer on my question: http://gallery.technet.microsoft.com/ScriptCenter/en-us/154dcae0-57a1-4c6e-8f9f-b215904485b7 Note that Vista/7 listed under Platforms very clearly says "Nope"...won't work. So the WMI deal seems like it's a no-go...

Being able to retrieve the installed path would be an upside as well, as right now my current code does not account for someone installing on another drive, or in a non-default directory.

Answer 1

The technet script you refer to perfectly works under Win 7 (with Python 2.5 32bits), and I really cannot see why it shouldn't.

Actually, the real weakness of the WMI approach is that it only lists products installed through the Windows Installer. So it's will not give you the full list. Many programs use different installers. Just compare the results between the (Select * from Win32_Product) and what is displayed in the Control Panel. So, unless you are sure that the program that interset you in your listing are installed with MSI, WMI is definitely not an answer.

So it may be not very pythonic, but the best way, as far as I know, is to use the registry as you've done. This is actually how the control panel works, so at least Windows considers it to be the most robust way to do it.

Answer 2

WMI is the correct way to look for installed programs as it will work across different versions of the OS and will be supported going forward. Looking for specific regkeys may work fine for specific versions of Windows but is not guaranteed to work in the future. Here is some simple python code to check for Box Sync which I just tried on Windows 7. Note that not all fields will be available for every product so be aware these will be 'None.'

import wmi
w = wmi.WMI()
for p in w.Win32_Product():
    if 'Box, Inc.' == p.Vendor and p.Caption and 'Box Sync' in p.Caption:
        print 'Installed {}'.format(p.Version)

The downside I have seen with WMI is it is very slow to start up.