samdmarshall/pyconfig

# Copyright (c) 2016, Samantha Marshall (http://pewpewthespells.com)
# All rights reserved.
#
# https://github.com/samdmarshall/pyconfig
#
# Redistribution and use in source and binary forms, with or without modification,
# are permitted provided that the following conditions are met:
#
# 1. Redistributions of source code must retain the above copyright notice, this
# list of conditions and the following disclaimer.
#
# 2. Redistributions in binary form must reproduce the above copyright notice,
# this list of conditions and the following disclaimer in the documentation and/or
# other materials provided with the distribution.
#
# 3. Neither the name of Samantha Marshall nor the names of its contributors may
# be used to endorse or promote products derived from this software without
# specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
# IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
# INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
# BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
# LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
# OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
# OF THE POSSIBILITY OF SUCH DAMAGE.

import collections

class OrderedDictionary(collections.MutableMapping):

    def __init__(self, *args, **kwargs):
        self.store = dict()
        self.key_storage = list()
        self.update(dict(*args, **kwargs))  # use the free update to set keys

    def __getitem__(self, key):
        return self.store[key]

    def __setitem__(self, key, value):
        if key not in self.key_storage:
            self.key_storage.append(key)
        self.store[key] = value

    def __delitem__(self, key): # pragma: no cover
        if key in self.key_storage:
            self.key_storage.remove(key)
        del self.store[key]

    def __iter__(self):
        return self.key_storage.__iter__()

    def __len__(self):
        return self.key_storage.__len__()

    def __str__(self): # pragma: no cover
        return self.store.__str__()

    def __contains__(self, item): # pragma: no cover
        return item in self.key_storage

    def __getattr__(self, attrib): # pragma: no cover
        return getattr(self.store, attrib)