[Python-Dev] Order that site-packages is added to sys.path (original) (raw)

Barry A. Warsaw barry@zope.com
Tue, 12 Feb 2002 11:46:26 -0500

"MAL" == M <mal@lemburg.com> writes:

MAL> I guess this is done for the same reason that e.g. /usr/local
MAL> is last in PATH on Unix: system top level programs and libs
MAL> should always have top priority. Otherwise, a user could
MAL> easily override a system program/lib by placing a new version
MAL> into the local dir which then gets picked up by other system
MAL> programs.

Well, hopefully you'd control who can write into /usr/local so that you could trust overrides being installed there. On a single user system, I usually do in fact put /usr/local/bin early in my path specifically because I do want to override older, buggier, system programs.

The analogy is similar in the Python situation. When I'm the only person using the system, and I'm in control of everything, being able to override the standard library is a very useful thing to do. When there's less trust in the environment I'm running in, or more sharing of common resources, it can be problematic.

-Barry