[Python-Dev] PEP 370, open questions

[Christian Heimes]

Mark Hammond wrote:
>> * Are the directories for Windows, Mac and Unix fine?
> 
> Regarding Windows, I personally think its OK (but I also personally think
> the status-quo is OK too).  As has already been mentioned in this thread,
> Windows actually provides an API you can call to determine various "well
> known" folders.  I assume the PEP literally means "the environment variable
> APPDATA" instead of the result of SHGetSpecialFolderPath(CSIDL_APPDATA); it
> might be worth mentioning that (and ideally *why* the env-var is preferred).
> Similarly, a justification for why CSIDL_APPDATA/%APPDATA% is preferred over
> CSIDL_LOCAL_APPDATA - ie, why we are suggesting Python is a "roaming"
> application (eg, this implies that in certain Unix environments, it is
> likely that ~/.local/ will follow users as they log into different machines
> on the network - I've no idea how true that is) 

Isn't SHGetSpecialFolderPath() XP and newer only? Python 2.6 is going to
support 2000 and newer. I've written a patch for the ntpath module which
adds a getshellfolders() function. The function uses SHGetFolderPathW to
build a dict of id to path mappings. The patch is available at
http://bugs.python.org/issue1763. Maybe you have some time to review it?

As far as I understand and remember the Windows API SHGetFolderPath()
and friends are retrieving the information from the registry. The shell
folder keys are (IIRC) REG_EXPAND_SZ keys which are expanded with the
function ExpandEnvironmentStrings(). So at the end CSIDL_APPDATA uses
the %APPDATA% env var -- unless I'm totally mistaken.

Or do you suggest that I'm using the win32 API calls instead of the env var?

Point taken! I'll justify why I view Python as a roaming app. All
company and university Linux boxes I've used in the past had exported
$HOME via NFS. So ~/.local is roamed.

> I'd recommend not; IIUC, Python's main binary directory isn't added to the
> path, but even if it was, it will only be useful if .py is also on PATHEXT.
> Either way though, I'd suggest that particular decision is outside the scope
> of the PEP and a question for the windows installer assuming the PEP be
> accepted.  Maybe some general hand-waving along the lines of "env vars on
> Windows are left to the installer, where such global issues are considered
> in a wider context" would do :)

*hehe* I love your idea.
It should be trivial to write a view lines of Python code which modify
PATH in HKCU. I'm going to write a simple example and drop it into
Tools/scripts/.

Christian

PS: Have you tested the new PCbuild directory for VS 2008? Martin said
that you know how to create a new set of base addresses for pre-linking.
dllbase_nt.txt is probably outdated.