#    Copyright 2014 Cloudscaling Group, Inc
#
#    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 copy


def update_dict(dict1, dict2):
    """Get a copy of union of two dicts."""
    res = copy.deepcopy(dict1)
    res.update(dict2)
    return res


def purge_dict(dict1, trash_keys):
    """Get a copy of dict, removed keys."""
    res = copy.deepcopy(dict1)
    for key in trash_keys:
        res.pop(key, None)
    return res


def patch_dict(dict1, dict2, trash_iter):
    """Get a copy of union of two dicts, removed keys."""
    res = update_dict(dict1, dict2)
    res = purge_dict(res, trash_iter)
    return res