Question

I have a module which is split roughly in half between utility type functions and core api functions. I need to have all of them in __all__ in order to have help() be useful, and also to specify which of the many functions/classes/etc in the module are for external use, but I also want to support from mymodule import * as a way to get just the core functionality into other modules. Is there a way to do that?

Answer 1

Almost. While you can’t have __all__ do double duty in this way, you can add your own virtual api module which can then be imported…

class fake_module(object):
    def __init__(self, name, *args):
        self.name = name
        self.__all__ = []
        all_objects = globals()
        for name in args:
            self.__dict__[name] = all_objects[name]
            self.__all__.append(name)
    def register(self):
        sys.modules["%s.%s" % (__name__, self.name)] = self

    fake_module('api', 'class1', 'class2', 'func3', 'exception4').register()

Then in the other modules instead of from mymodule import * you can do from mymodule.api import * to get just the desired subset while still keeping everything in a single module.

Note: from ... import * is not usually good practice, and should be used with great care and only with modules/packages that explicity state that they have been designed with such usage in mind.