[Python-Dev] PEP 370, open questions (original) (raw)

Christian Heimes lists at cheimes.de
Thu Jan 17 12:08:26 CET 2008

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(CSIDLAPPDATA); it might be worth mentioning that (and ideally why the env-var is preferred). Similarly, a justification for why CSIDLAPPDATA/%APPDATA% is preferred over CSIDLLOCALAPPDATA - 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.

More information about the Python-Dev mailing list