1 # Copyright (c) 2009 Raymond Hettinger 2 # 3 # Permission is hereby granted, free of charge, to any person 4 # obtaining a copy of this software and associated documentation files 5 # (the "Software"), to deal in the Software without restriction, 6 # including without limitation the rights to use, copy, modify, merge, 7 # publish, distribute, sublicense, and/or sell copies of the Software, 8 # and to permit persons to whom the Software is furnished to do so, 9 # subject to the following conditions: 10 # 11 # The above copyright notice and this permission notice shall be 12 # included in all copies or substantial portions of the Software. 13 # 14 # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 15 # EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES 16 # OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 17 # NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT 18 # HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, 19 # WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 20 # FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR 21 # OTHER DEALINGS IN THE SOFTWARE. 22 23 from UserDict import DictMixin 24 25 class OrderedDict(dict, DictMixin): 26 27 def __init__(self, *args, **kwds): 28 if len(args) > 1: 29 raise TypeError('expected at most 1 arguments, got %d' % len(args)) 30 try: 31 self.__end 32 except AttributeError: 33 self.clear() 34 self.update(*args, **kwds) 35 36 def clear(self): 37 self.__end = end = [] 38 end += [None, end, end] # sentinel node for doubly linked list 39 self.__map = {} # key --> [key, prev, next] 40 dict.clear(self) 41 42 def __setitem__(self, key, value): 43 if key not in self: 44 end = self.__end 45 curr = end[1] 46 curr[2] = end[1] = self.__map[key] = [key, curr, end] 47 dict.__setitem__(self, key, value) 48 49 def __delitem__(self, key): 50 dict.__delitem__(self, key) 51 key, prev, next = self.__map.pop(key) 52 prev[2] = next 53 next[1] = prev 54 55 def __iter__(self): 56 end = self.__end 57 curr = end[2] 58 while curr is not end: 59 yield curr[0] 60 curr = curr[2] 61 62 def __reversed__(self): 63 end = self.__end 64 curr = end[1] 65 while curr is not end: 66 yield curr[0] 67 curr = curr[1] 68 69 def popitem(self, last=True): 70 if not self: 71 raise KeyError('dictionary is empty') 72 if last: 73 key = reversed(self).next() 74 else: 75 key = iter(self).next() 76 value = self.pop(key) 77 return key, value 78 79 def __reduce__(self): 80 items = [[k, self[k]] for k in self] 81 tmp = self.__map, self.__end 82 del self.__map, self.__end 83 inst_dict = vars(self).copy() 84 self.__map, self.__end = tmp 85 if inst_dict: 86 return (self.__class__, (items,), inst_dict) 87 return self.__class__, (items,) 88 89 def keys(self): 90 return list(self) 91 92 setdefault = DictMixin.setdefault 93 update = DictMixin.update 94 pop = DictMixin.pop 95 values = DictMixin.values 96 items = DictMixin.items 97 iterkeys = DictMixin.iterkeys 98 itervalues = DictMixin.itervalues 99 iteritems = DictMixin.iteritems 100 101 def __repr__(self): 102 if not self: 103 return '%s()' % (self.__class__.__name__,) 104 return '%s(%r)' % (self.__class__.__name__, self.items()) 105 106 def copy(self): 107 return self.__class__(self) 108 109 @classmethod 110 def fromkeys(cls, iterable, value=None): 111 d = cls() 112 for key in iterable: 113 d[key] = value 114 return d 115 116 def __eq__(self, other): 117 if isinstance(other, OrderedDict): 118 if len(self) != len(other): 119 return False 120 for p, q in zip(self.items(), other.items()): 121 if p != q: 122 return False 123 return True 124 return dict.__eq__(self, other) 125 126 def __ne__(self, other): 127 return not self == other 128
