# vim: tabstop=4 shiftwidth=4 softtabstop=4

# Copyright 2011 OpenStack LLC.
# All Rights Reserved.
#
#    Licensed under the Apache License, Version 2.0 (the "License"); you may
#    not use this file except in compliance with the License. You may obtain
#    a copy of the License at
#
#         http://www.apache.org/licenses/LICENSE-2.0
#
#    Unless required by applicable law or agreed to in writing, software
#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
#    License for the specific language governing permissions and limitations
#    under the License.

"""
Import related utilities and helper functions.
"""

import sys


def import_class(import_str):
    """Returns a class from a string including module and class"""
    mod_str, _sep, class_str = import_str.rpartition('.')
    try:
        __import__(mod_str)
        return getattr(sys.modules[mod_str], class_str)
    except (ImportError, ValueError, AttributeError), exc:
        raise ImportError('Class %s cannot be found (%s)' %
                         (class_str, str(exc)))


def import_object(import_str, *args, **kwargs):
    """Import a class and return an instance of it."""
    return import_class(import_str)(*args, **kwargs)


def import_module(import_str):
    """Import a module."""
    __import__(import_str)
    return sys.modules[import_str]
