I personally make heavy use of the command line and continue to install python to %ProgramFiles%. I find the space in the pathname to be a non-issue. After %programfiles%\Python26 and %programfiles%\Python26\Scripts are added to the path, and .py is added to PATHEXT, everything behaves very well. I use cmd.exe and powershell, and both of these shells handle the spaces well enough, including supporting tab completion (so if one _does_ need to reference a path with a space in it, it's not even necessary to know what the syntax is).

With Python 3, support for version of Windows prior to XP (including DOS) has been deprecated, so it seems to me rather regressive to insist on DOS 8.3 compatibility.

I concur that early on, I would struggle with the spaces if Python was installed to %programfiles%, but since about Python 2.3 or 2.4, I've had only the one problem with setuptools, and that has been fixed.

IMO, supporting installation to Program Files is not only the right thing to do, but it will make Python more robust.

On the other hand, I may be unaware of any use cases which are still problematic. Perhaps there are still many who always launch python using \python26\python. That command would then become "\program files\python26\python". I find that to be a small price to pay for the gains in security and consistency (and compartmentalization).

Furthermore, a heavy command-line user is probably also a power user, and if typing "C:\Program Files\Python26\Python" is too onerous, I'm sure he can find a workaround, such as setting the path, creating hardlinks or symlinks, setting up aliases, etc.

I agree it's a shame the de-facto location for Programs on Windows isn't a more amenable name.

Personally, I always override the default installation directory, so it matters to me little what choice is made for the default, but on the whole, I believe users would be better off with Python in Program Files.