Synnefo

from imp import find_module, load_module

_modules = {}

def imp_module(fullname):

    if fullname in _modules:

        return _modules[fullname]

    components = fullname.split('.')

    if not components:

        raise ValueError('invalid module name')

    module = None

    modulepath = []

    for name in components:

        if not name:

            raise ValueError("Relative paths not allowed")

        modulepath.append(name)

        modulename = '.'.join(modulepath)

        if modulename in _modules:

            module = _modules[modulename]

        elif hasattr(module, name):

            module = getattr(module, name)

        elif not hasattr(module, '__path__'):

            m = find_module(name)

            module = load_module(modulename, *m)

        else:

            try:

                m = find_module(name, module.__path__)

                module = load_module(modulename, *m)

            except ImportError:

                m = "No module '%s' in '%s'" % (name, module.__path__)

                raise ImportError(m)

        _modules[modulename] = module

    return module

def list_modules():

    return sorted(_modules.keys())