-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 10/28/2011 05:10 PM, Chris McDonough wrote: >> Why not modify sys.prefix? >> - -------------------------- >> >> As discussed above under `Backwards Compatibility`_, this PEP proposes >> to add ``sys.site_prefix`` as "the prefix relative to which >> site-package directories are found". This maintains compatibility with >> the documented meaning of ``sys.prefix`` (as the location relative to >> which the standard library can be found), but means that code assuming >> that site-packages directories are found relative to ``sys.prefix`` >> will not respect the virtual environment correctly. >> >> Since it is unable to modify ``distutils``/``sysconfig``, >> `virtualenv`_ is forced to instead re-point ``sys.prefix`` at the >> virtual environment. >> >> An argument could be made that this PEP should follow virtualenv's >> lead here (and introduce something like ``sys.base_prefix`` to point >> to the standard library and header files), since virtualenv already >> does this and it doesn't appear to have caused major problems with >> existing code. >> >> Another argument in favor of this is that it would be preferable to >> err on the side of greater, rather than lesser, isolation. Changing >> ``sys.prefix`` to point to the virtual environment and introducing a >> new ``sys.base_prefix`` attribute would err on the side of greater >> isolation in the face of existing code's use of ``sys.prefix``. > > It would seem to make sense to me to err on the side of greater > isolation, introducing sys.base_prefix to indicate the base prefix (as > opposed to sys.site_prefix indicating the venv prefix). Bugs introduced > via a semi-isolated virtual environment are very difficult to > troubleshoot. It would also make changes to existing code unnecessary. > I have encountered no issues with virtualenv doing this so far.
I'm convinced that this is the better tradeoff. I'll begin working on a branch of the reference implementation that does things this way. Thanks for the feedback. Carl -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAk6uq2IACgkQ8W4rlRKtE2chHQCgik136LkoQ/JE6b3r4astWcog kYYAoN7ESaPlZOaYeok5t0i9hMkb2L4g =/Rn1 -----END PGP SIGNATURE----- _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
