74 lines
2.3 KiB
Python
74 lines
2.3 KiB
Python
# Copyright 2011 OpenStack Foundation.
|
|
# 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
|
|
import traceback
|
|
|
|
|
|
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 (ValueError, AttributeError):
|
|
raise ImportError('Class %s cannot be found (%s)' %
|
|
(class_str,
|
|
traceback.format_exception(*sys.exc_info())))
|
|
|
|
|
|
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_object_ns(name_space, import_str, *args, **kwargs):
|
|
"""Tries to import object from default namespace.
|
|
|
|
Imports a class and return an instance of it, first by trying
|
|
to find the class in a default namespace, then failing back to
|
|
a full path if not found in the default namespace.
|
|
"""
|
|
import_value = "%s.%s" % (name_space, import_str)
|
|
try:
|
|
return import_class(import_value)(*args, **kwargs)
|
|
except ImportError:
|
|
return import_class(import_str)(*args, **kwargs)
|
|
|
|
|
|
def import_module(import_str):
|
|
"""Import a module."""
|
|
__import__(import_str)
|
|
return sys.modules[import_str]
|
|
|
|
|
|
def import_versioned_module(version, submodule=None):
|
|
module = 'ironic_python_agent.v%s' % version
|
|
if submodule:
|
|
module = '.'.join((module, submodule))
|
|
return import_module(module)
|
|
|
|
|
|
def try_import(import_str, default=None):
|
|
"""Try to import a module and if it fails return default."""
|
|
try:
|
|
return import_module(import_str)
|
|
except ImportError:
|
|
return default
|