[Python-Dev] Importing .pyc in -O mode and vice versa (original) (raw)

Giovanni Bajo rasky at develer.com
Mon Nov 6 20:54:35 CET 2006

Armin Rigo wrote:

Typical example: someone in the project removes a .py file, and checks in this change; someone else does an 'svn up', which kills the .py in his working copy, but not the .pyc. These stale .pyc's cause pain, e.g. by shadowing the real module (further down sys.path), or simply by preventing the project's developers from realizing that they forgot to fix some imports. We regularly had obscure problems that went away as soon as we deleted all .pyc files around, but I cannot comment more on that because we never really investigated.

This is exactly why I always use this module:

================== nobarepyc.py ============================ #!/usr/bin/env python #-- coding: utf-8 -- import ihooks import os

class _NoBarePycHooks(ihooks.Hooks): def load_compiled(self, name, filename, *args, **kwargs): sourcefn = os.path.splitext(filename)[0] + ".py" if not os.path.isfile(sourcefn): raise ImportError('forbidden import of bare .pyc file: %r' % filename) return ihooks.Hooks.load_compiled(name, filename, *args, **kwargs)

ihooks.ModuleImporter(ihooks.ModuleLoader(_NoBarePycHooks())).install() ================== /nobarepyc.py ============================

Just import it before importing anything else (or in site.py if you prefer) and you'll be done.

Ah, it doesn't work with zipimports...

Giovanni Bajo

More information about the Python-Dev mailing list