Extending the import mechanism - what is recommended?

[Steve Holden]

dbr517 at gmail.com wrote:
> I need to extend the import mechanism to support another file type.
> I've already written the necessary C library to read the file and
> return a python code object.
> 
> I found one example which just sub-classed imputil.ImportManager like
> this:
> 
> from myLib import pye_code as pye_code
> class MyImporter(imputil.ImportManager):
>     def __init__(self):
>         imputil.ImportManager.__init__(self)
>         self.add_suffix('.pye', self.import_pye)
>         self.install()
> 
>     def import_pye(self, filepath, fileinfo, filename):
>         data = pye_code(filepath)
>         return 0, data, {}
> 
> This actually works fine if the module is just a few lines of code,
> but it won't chain to the "built-in" importers; if the module that I'm
> importing does something as simple as 'import re', it fails.
> 
> It may be that my confusion here is because (even after reading the
> code), I'm not clear on the purposes of imputil.ImportManager vs.
> imputil.Importer :-(
> 
> What is the "preferred" way to do this type of extension?  One other
> note; at this time, I just need to import individual module files with
> this extension; I don't need to import packages.
> 
Here's an importer I wrote some time ago to bring modules in from a 
relational database. I won't trouble you with the code to compile the 
modules/packages and add them into the database, but perhaps the 
attached code will be enough to show you what you are doing that's not 
working.

regards
  Steve
-- 
Steve Holden        +1 571 484 6266   +1 800 494 3119
Holden Web LLC              http://www.holdenweb.com/
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