Nick Coghlan wrote:
> With the new abstract base classes in Py3k, I can see it being
> worthwhile to have a standard mechanism to allow callbacks to be
> registered for execution when particular modules are first imported.
>
> For example, to handle the commented out case above:
>
> @imp.imported('decimal')
> def register(decimal):
> Inexact.register(decimal.Decimal)
Your proposed hook is a post import hook. Could we use a pre import hook
that is called before the module is loaded? I can think of several use
cases:
* modify the search path sys.path dynamically
* issue deprecation warnings
* modify the name of the module which is going to be imported
* return a different module
def preImportHook(name: str) -> (None, str, ModuleType instance):
"""The pre import hook is run before the module is loaded
and inserted into sys modules
Return values::
* None
No special treatment
* string: new_name
The module "new_name" is loaded instead of the module "name"
* module object
The module object is inserted into sys.modules and returned by
the import statement.
* raise Exception
The import is stopped and a chained ImportError is raised
"""
The pre import hook could be useful for
http://www.python.org/dev/peps/pep-0364/.
The pre import hook can probably be implemented in pure Python with a
meta path hook as described in http://www.python.org/dev/peps/pep-0302/.
I see the pre import hook as a lightweight meta path hook with an easy
to use interface.
Christian
_______________________________________________
Python-3000 mailing list
Python-3000@python.org
http://mail.python.org/mailman/listinfo/python-3000
Unsubscribe:
http://mail.python.org/mailman/options/python-3000/archive%40mail-archive.com
