[Distutils] installing .py plugins to an alternate directory

[P.J. Eby]

At 01:18 AM 12/5/2009 +0100, Andrew Dalke wrote:
>It appears that pkg_resources does some caching, including using 
>linecache. I can't tell how well it would work if our pluging 
>packages were updated after the main server was running.

If you need to ensure that you get a fresh list of plugins each time, 
you can use "for entry_point in 
pkg_resources.WorkingSet().iter_entry_points(...)".  Or more 
precisely, you can create a new WorkingSet() whenever you want to 
start over with a clean cache.

(Btw, the only thing pkg_resources uses linecache for is to ensure 
that the source of a script loaded from an alternate location is 
viewable in linecache as though it came from the location the script 
was run from.  This is a debugging aid only, and doesn't have any 
effect on anything that's not trying to dump out source code lines 
(such as an error reporting tool, or the Python debugger).)