[Python-ideas] Importing orphaned bytecode files (was: disabling .pyc and .pyo files)

[Guido van Rossum]

On Wed, Dec 9, 2009 at 11:07 AM, Jared Grubb <jared.grubb at gmail.com> wrote:
>
> On 8 Dec 2009, at 13:44, Ben Finney wrote:
>
> * A new attribute ‘sys.import_orphaned_bytecode’. If set ‘True’, the
>  interpreter follows the current behaviour. If ‘False’, any bytecode
>  file satisfies an import only if it has a corresponding source file
>  (where “corresponding” means “this source file would, if compiled,
>  result in a bytecode file replacing this one”).
>
> One problem with a sys flag is that it's a global setting. Suppose a package
> is distributed with only pyc/pyo files, then the top-level __init__.py might
> flip the switch such that its sub-files can get imported from the pyc/pyo
> files. But you wouldnt want that flag to persist beyond that.

I'm not sure that there are any use cases that require using
conflicting values of this setting for different packages.

> Another idea is to use a new file extension, which isnt the best solution,
> but allows the creator to explicitly set what behavior they intended for
> their files:
>   * if a foo.py file exists, then use the existing foo.pyc/pyo as is done
> today
>   * if a foo.py file does not exist, but a foo.pyxxx exists, use it (but
> file.pyc/pyo is never used, unlike today)
> (pyxxx is a placeholder for whatever would be a reasonable name)

It's a much bigger change, but using a different extension would
probably remove the need for a flag. It would also help with some
tools that hide .pyc/.pyo files from view (e.g. the typical
.svnignore).

-- 
--Guido van Rossum (python.org/~guido)