[mod_python] python path and 3.3

2006/12/2, Graham Dumpleton <grahamd at dscpl.com.au>:
>
> On 02/12/2006, at 10:57 AM, Clodoaldo wrote:
>
> >> Ok, I did it and now this works:
> >>
> >> import constants as C
> >>
> >> But this does not work:
> >>
> >> from mod_python import apache
> >> C = apache.import_module('constants.py')
> >>
> >
> > Changed it to:
> >
> > from mod_python import apache
> > C = apache.import_module('~/mod/constants.py')
> >
> > And it works.
>
> The apache.import_module() function is doing double duty in allowing
> either a module name or a path for a file (including extension). For a
> path it has to be able to be distinguishable from a module or module
> within

I should have tried it. This works:

from mod_python import apache
C = apache.import_module('constants')

> package name. Thus, for a path, can only use:
>
>    /some/path/module.py
>    ~/some/path/module.py
>    ./some/path/module.py
>    ../some/path/module.py
>
> For anything else it assumes it is a normal module import. For
> 'constants.py'
> that thus means it thinks you are wanting to import a submodule
> called 'py'
> from a package called 'constants'.
>
> There are a few other quirks with the new importer. The first is that
> when a
> path is specified, you don't actually need to use a .py extension.
> This means
> for example that the mpservlets package which uses a .mps extension
> could
> quite easily be rewritten to use the new module importer rather than
> its own
> and get all the benefit of the full depth checks on module reloading.
> In other
> words:
>
>    module = apache.import_module("/some/path/servlet.mps")
>
> will work.
>
> This may be useful if you don't want to use a .py extension and want
> to use
> something else to hide the fact that Python is being used.
>
> Another strange characteristic of the new module importer, although this
> also actually works in more recent Python versions if using __import__
> (),
> although not perhaps on all platforms, is that one can use a '/' to
> refer to a
> module name in a subdirectory somewhere on the module search path.
>
> What this means is that if you had used:
>
>    PythonOption mod_python.importer.path "['~/']"
>
> rather than:
>
>    PythonOption mod_python.importer.path "['~/mod']"
>
> you could then have said:
>
>    apache.import_module('mod/constants')
>
> Note that I haven't used a '.py' extension. In some way this is like
> having a
> package, but the big difference is that the 'mod' directory doesn't
> have to be
> an actual package, ie., no __init__.py file is required.
>
> This method can thus be used to create a namespace for modules still,
> ie.,
> by using a subdirectory, but since a package isn't being used, automatic
> module reloading still works.
>
> Since the same works with __import__() for some versions of Python,
> falling back to using __import__() may be useful if you are trying to do
> testing outside of mod_python.
>
> Graham
>

This topic is now a very complete tutorial on the new 3.3 importer. It
can make a valuable article in the wiki, if properly cleaned.

-- 
Clodoaldo Pinto Neto