1 """Drop-in replacement for collections.OrderedDict by Raymond Hettinger 2 3 http://code.activestate.com/recipes/576693/ 4 5 """ 6 from UserDict import DictMixin 7 8 # Modified from original to support Python 2.4, see 9 # http://code.google.com/p/simplejson/issues/detail?id=53 10 try: 11 all 12 except NameError: 13 def all(seq): 14 for elem in seq: 15 if not elem: 16 return False 17 return True 18 19 class OrderedDict(dict, DictMixin): 20 21 def __init__(self, *args, **kwds): 22 if len(args) > 1: 23 raise TypeError('expected at most 1 arguments, got %d' % len(args)) 24 try: 25 self.__end 26 except AttributeError: 27 self.clear() 28 self.update(*args, **kwds) 29 30 def clear(self): 31 self.__end = end = [] 32 end += [None, end, end] # sentinel node for doubly linked list 33 self.__map = {} # key --> [key, prev, next] 34 dict.clear(self) 35 36 def __setitem__(self, key, value): 37 if key not in self: 38 end = self.__end 39 curr = end[1] 40 curr[2] = end[1] = self.__map[key] = [key, curr, end] 41 dict.__setitem__(self, key, value) 42 43 def __delitem__(self, key): 44 dict.__delitem__(self, key) 45 key, prev, next = self.__map.pop(key) 46 prev[2] = next 47 next[1] = prev 48 49 def __iter__(self): 50 end = self.__end 51 curr = end[2] 52 while curr is not end: 53 yield curr[0] 54 curr = curr[2] 55 56 def __reversed__(self): 57 end = self.__end 58 curr = end[1] 59 while curr is not end: 60 yield curr[0] 61 curr = curr[1] 62 63 def popitem(self, last=True): 64 if not self: 65 raise KeyError('dictionary is empty') 66 # Modified from original to support Python 2.4, see 67 # http://code.google.com/p/simplejson/issues/detail?id=53 68 if last: 69 key = reversed(self).next() 70 else: 71 key = iter(self).next() 72 value = self.pop(key) 73 return key, value 74 75 def __reduce__(self): 76 items = [[k, self[k]] for k in self] 77 tmp = self.__map, self.__end 78 del self.__map, self.__end 79 inst_dict = vars(self).copy() 80 self.__map, self.__end = tmp 81 if inst_dict: 82 return (self.__class__, (items,), inst_dict) 83 return self.__class__, (items,) 84 85 def keys(self): 86 return list(self) 87 88 setdefault = DictMixin.setdefault 89 update = DictMixin.update 90 pop = DictMixin.pop 91 values = DictMixin.values 92 items = DictMixin.items 93 iterkeys = DictMixin.iterkeys 94 itervalues = DictMixin.itervalues 95 iteritems = DictMixin.iteritems 96 97 def __repr__(self): 98 if not self: 99 return '%s()' % (self.__class__.__name__,) 100 return '%s(%r)' % (self.__class__.__name__, self.items()) 101 102 def copy(self): 103 return self.__class__(self) 104 105 @classmethod 106 def fromkeys(cls, iterable, value=None): 107 d = cls() 108 for key in iterable: 109 d[key] = value 110 return d 111 112 def __eq__(self, other): 113 if isinstance(other, OrderedDict): 114 return len(self)==len(other) and \ 115 all(p==q for p, q in zip(self.items(), other.items())) 116 return dict.__eq__(self, other) 117 118 def __ne__(self, other): 119 return not self == other 120
