1# Copyright (c) 2006 The Regents of The University of Michigan
2# All rights reserved.
3#
4# Redistribution and use in source and binary forms, with or without
5# modification, are permitted provided that the following conditions are
6# met: redistributions of source code must retain the above copyright
7# notice, this list of conditions and the following disclaimer;
8# redistributions in binary form must reproduce the above copyright
9# notice, this list of conditions and the following disclaimer in the
10# documentation and/or other materials provided with the distribution;
11# neither the name of the copyright holders nor the names of its
12# contributors may be used to endorse or promote products derived from
13# this software without specific prior written permission.
14#
15# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
18# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
19# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
20# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
21# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
25# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26#
27# Authors: Nathan Binkert
28
29from __future__ import print_function
30
31__all__ = [ 'attrdict', 'multiattrdict', 'optiondict' ]
32
33class attrdict(dict):
34    """Wrap dict, so you can use attribute access to get/set elements"""
35    def __getattr__(self, attr):
36        if attr in self:
37            return self.__getitem__(attr)
38        return super(attrdict, self).__getattribute__(attr)
39
40    def __setattr__(self, attr, value):
41        if attr in dir(self) or attr.startswith('_'):
42            return super(attrdict, self).__setattr__(attr, value)
43        return self.__setitem__(attr, value)
44
45    def __delattr__(self, attr):
46        if attr in self:
47            return self.__delitem__(attr)
48        return super(attrdict, self).__delattr__(attr)
49
50    def __getstate__(self):
51        return dict(self)
52
53    def __setstate__(self, state):
54        self.update(state)
55
56class multiattrdict(attrdict):
57    """Wrap attrdict so that nested attribute accesses automatically create
58    nested dictionaries."""
59    def __getattr__(self, attr):
60        try:
61            return super(multiattrdict, self).__getattr__(attr)
62        except AttributeError:
63            if attr.startswith('_'):
64                raise
65
66            d = multiattrdict()
67            setattr(self, attr, d)
68            return d
69
70class optiondict(attrdict):
71    """Modify attrdict so that a missing attribute just returns None"""
72    def __getattr__(self, attr):
73        try:
74            return super(optiondict, self).__getattr__(attr)
75        except AttributeError:
76            return None
77
78if __name__ == '__main__':
79    x = attrdict()
80    x.y = 1
81    x['z'] = 2
82    print(x['y'], x.y)
83    print(x['z'], x.z)
84    print(dir(x))
85    print(x)
86
87    print()
88
89    del x['y']
90    del x.z
91    print(dir(x))
92    print(x)
93
94    print()
95    print("multiattrdict")
96    x = multiattrdict()
97    x.x.x.x = 9
98    x.y.z = 9
99    print(x)
100    print(x.y)
101    print(x.y.z)
102    print(x.z.z)
103