attrdict.py revision 7459:da32c2b05648
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 29__all__ = [ 'attrdict', 'multiattrdict', 'optiondict' ] 30 31class attrdict(dict): 32 """Wrap dict, so you can use attribute access to get/set elements""" 33 def __getattr__(self, attr): 34 if attr in self: 35 return self.__getitem__(attr) 36 return super(attrdict, self).__getattribute__(attr) 37 38 def __setattr__(self, attr, value): 39 if attr in dir(self) or attr.startswith('_'): 40 return super(attrdict, self).__setattr__(attr, value) 41 return self.__setitem__(attr, value) 42 43 def __delattr__(self, attr): 44 if attr in self: 45 return self.__delitem__(attr) 46 return super(attrdict, self).__delattr__(attr) 47 48 def __getstate__(self): 49 return dict(self) 50 51 def __setstate__(self, state): 52 self.update(state) 53 54class multiattrdict(attrdict): 55 """Wrap attrdict so that nested attribute accesses automatically create 56 nested dictionaries.""" 57 def __getattr__(self, attr): 58 try: 59 return super(multiattrdict, self).__getattr__(attr) 60 except AttributeError: 61 if attr.startswith('_'): 62 raise 63 64 d = multiattrdict() 65 setattr(self, attr, d) 66 return d 67 68class optiondict(attrdict): 69 """Modify attrdict so that a missing attribute just returns None""" 70 def __getattr__(self, attr): 71 try: 72 return super(optiondict, self).__getattr__(attr) 73 except AttributeError: 74 return None 75 76if __name__ == '__main__': 77 x = attrdict() 78 x.y = 1 79 x['z'] = 2 80 print x['y'], x.y 81 print x['z'], x.z 82 print dir(x) 83 print x 84 85 print 86 87 del x['y'] 88 del x.z 89 print dir(x) 90 print(x) 91 92 print 93 print "multiattrdict" 94 x = multiattrdict() 95 x.x.x.x = 9 96 x.y.z = 9 97 print x 98 print x.y 99 print x.y.z 100 print x.z.z 101