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| 1 # Backport of OrderedDict() class that runs on Python 2.4, 2.5, 2.6, 2.7 and pyp
y. |
| 2 # Passes Python2.7's test suite and incorporates all the latest updates. |
| 3 # Copyright 2009 Raymond Hettinger, released under the MIT License. |
| 4 # http://code.activestate.com/recipes/576693/ |
| 5 try: |
| 6 from thread import get_ident as _get_ident |
| 7 except ImportError: |
| 8 from dummy_thread import get_ident as _get_ident |
| 9 |
| 10 try: |
| 11 from _abcoll import KeysView, ValuesView, ItemsView |
| 12 except ImportError: |
| 13 pass |
| 14 |
| 15 |
| 16 class OrderedDict(dict): |
| 17 'Dictionary that remembers insertion order' |
| 18 # An inherited dict maps keys to values. |
| 19 # The inherited dict provides __getitem__, __len__, __contains__, and get. |
| 20 # The remaining methods are order-aware. |
| 21 # Big-O running times for all methods are the same as for regular dictionari
es. |
| 22 |
| 23 # The internal self.__map dictionary maps keys to links in a doubly linked l
ist. |
| 24 # The circular doubly linked list starts and ends with a sentinel element. |
| 25 # The sentinel element never gets deleted (this simplifies the algorithm). |
| 26 # Each link is stored as a list of length three: [PREV, NEXT, KEY]. |
| 27 |
| 28 def __init__(self, *args, **kwds): |
| 29 '''Initialize an ordered dictionary. Signature is the same as for |
| 30 regular dictionaries, but keyword arguments are not recommended |
| 31 because their insertion order is arbitrary. |
| 32 |
| 33 ''' |
| 34 if len(args) > 1: |
| 35 raise TypeError('expected at most 1 arguments, got %d' % len(args)) |
| 36 try: |
| 37 self.__root |
| 38 except AttributeError: |
| 39 self.__root = root = [] # sentinel node |
| 40 root[:] = [root, root, None] |
| 41 self.__map = {} |
| 42 self.__update(*args, **kwds) |
| 43 |
| 44 def __setitem__(self, key, value, dict_setitem=dict.__setitem__): |
| 45 'od.__setitem__(i, y) <==> od[i]=y' |
| 46 # Setting a new item creates a new link which goes at the end of the lin
ked |
| 47 # list, and the inherited dictionary is updated with the new key/value p
air. |
| 48 if key not in self: |
| 49 root = self.__root |
| 50 last = root[0] |
| 51 last[1] = root[0] = self.__map[key] = [last, root, key] |
| 52 dict_setitem(self, key, value) |
| 53 |
| 54 def __delitem__(self, key, dict_delitem=dict.__delitem__): |
| 55 'od.__delitem__(y) <==> del od[y]' |
| 56 # Deleting an existing item uses self.__map to find the link which is |
| 57 # then removed by updating the links in the predecessor and successor no
des. |
| 58 dict_delitem(self, key) |
| 59 link_prev, link_next, key = self.__map.pop(key) |
| 60 link_prev[1] = link_next |
| 61 link_next[0] = link_prev |
| 62 |
| 63 def __iter__(self): |
| 64 'od.__iter__() <==> iter(od)' |
| 65 root = self.__root |
| 66 curr = root[1] |
| 67 while curr is not root: |
| 68 yield curr[2] |
| 69 curr = curr[1] |
| 70 |
| 71 def __reversed__(self): |
| 72 'od.__reversed__() <==> reversed(od)' |
| 73 root = self.__root |
| 74 curr = root[0] |
| 75 while curr is not root: |
| 76 yield curr[2] |
| 77 curr = curr[0] |
| 78 |
| 79 def clear(self): |
| 80 'od.clear() -> None. Remove all items from od.' |
| 81 try: |
| 82 for node in self.__map.itervalues(): |
| 83 del node[:] |
| 84 root = self.__root |
| 85 root[:] = [root, root, None] |
| 86 self.__map.clear() |
| 87 except AttributeError: |
| 88 pass |
| 89 dict.clear(self) |
| 90 |
| 91 def popitem(self, last=True): |
| 92 '''od.popitem() -> (k, v), return and remove a (key, value) pair. |
| 93 Pairs are returned in LIFO order if last is true or FIFO order if false. |
| 94 |
| 95 ''' |
| 96 if not self: |
| 97 raise KeyError('dictionary is empty') |
| 98 root = self.__root |
| 99 if last: |
| 100 link = root[0] |
| 101 link_prev = link[0] |
| 102 link_prev[1] = root |
| 103 root[0] = link_prev |
| 104 else: |
| 105 link = root[1] |
| 106 link_next = link[1] |
| 107 root[1] = link_next |
| 108 link_next[0] = root |
| 109 key = link[2] |
| 110 del self.__map[key] |
| 111 value = dict.pop(self, key) |
| 112 return key, value |
| 113 |
| 114 # -- the following methods do not depend on the internal structure -- |
| 115 |
| 116 def keys(self): |
| 117 'od.keys() -> list of keys in od' |
| 118 return list(self) |
| 119 |
| 120 def values(self): |
| 121 'od.values() -> list of values in od' |
| 122 return [self[key] for key in self] |
| 123 |
| 124 def items(self): |
| 125 'od.items() -> list of (key, value) pairs in od' |
| 126 return [(key, self[key]) for key in self] |
| 127 |
| 128 def iterkeys(self): |
| 129 'od.iterkeys() -> an iterator over the keys in od' |
| 130 return iter(self) |
| 131 |
| 132 def itervalues(self): |
| 133 'od.itervalues -> an iterator over the values in od' |
| 134 for k in self: |
| 135 yield self[k] |
| 136 |
| 137 def iteritems(self): |
| 138 'od.iteritems -> an iterator over the (key, value) items in od' |
| 139 for k in self: |
| 140 yield (k, self[k]) |
| 141 |
| 142 def update(*args, **kwds): |
| 143 '''od.update(E, **F) -> None. Update od from dict/iterable E and F. |
| 144 |
| 145 If E is a dict instance, does: for k in E: od[k] = E[k] |
| 146 If E has a .keys() method, does: for k in E.keys(): od[k] = E[k] |
| 147 Or if E is an iterable of items, does: for k, v in E: od[k] = v |
| 148 In either case, this is followed by: for k, v in F.items(): od[k] =
v |
| 149 |
| 150 ''' |
| 151 if len(args) > 2: |
| 152 raise TypeError('update() takes at most 2 positional ' |
| 153 'arguments (%d given)' % (len(args),)) |
| 154 elif not args: |
| 155 raise TypeError('update() takes at least 1 argument (0 given)') |
| 156 self = args[0] |
| 157 # Make progressively weaker assumptions about "other" |
| 158 other = () |
| 159 if len(args) == 2: |
| 160 other = args[1] |
| 161 if isinstance(other, dict): |
| 162 for key in other: |
| 163 self[key] = other[key] |
| 164 elif hasattr(other, 'keys'): |
| 165 for key in other.keys(): |
| 166 self[key] = other[key] |
| 167 else: |
| 168 for key, value in other: |
| 169 self[key] = value |
| 170 for key, value in kwds.items(): |
| 171 self[key] = value |
| 172 |
| 173 __update = update # let subclasses override update without breaking __init_
_ |
| 174 |
| 175 __marker = object() |
| 176 |
| 177 def pop(self, key, default=__marker): |
| 178 '''od.pop(k[,d]) -> v, remove specified key and return the corresponding
value. |
| 179 If key is not found, d is returned if given, otherwise KeyError is raise
d. |
| 180 |
| 181 ''' |
| 182 if key in self: |
| 183 result = self[key] |
| 184 del self[key] |
| 185 return result |
| 186 if default is self.__marker: |
| 187 raise KeyError(key) |
| 188 return default |
| 189 |
| 190 def setdefault(self, key, default=None): |
| 191 'od.setdefault(k[,d]) -> od.get(k,d), also set od[k]=d if k not in od' |
| 192 if key in self: |
| 193 return self[key] |
| 194 self[key] = default |
| 195 return default |
| 196 |
| 197 def __repr__(self, _repr_running={}): |
| 198 'od.__repr__() <==> repr(od)' |
| 199 call_key = id(self), _get_ident() |
| 200 if call_key in _repr_running: |
| 201 return '...' |
| 202 _repr_running[call_key] = 1 |
| 203 try: |
| 204 if not self: |
| 205 return '%s()' % (self.__class__.__name__,) |
| 206 return '%s(%r)' % (self.__class__.__name__, self.items()) |
| 207 finally: |
| 208 del _repr_running[call_key] |
| 209 |
| 210 def __reduce__(self): |
| 211 'Return state information for pickling' |
| 212 items = [[k, self[k]] for k in self] |
| 213 inst_dict = vars(self).copy() |
| 214 for k in vars(OrderedDict()): |
| 215 inst_dict.pop(k, None) |
| 216 if inst_dict: |
| 217 return (self.__class__, (items,), inst_dict) |
| 218 return self.__class__, (items,) |
| 219 |
| 220 def copy(self): |
| 221 'od.copy() -> a shallow copy of od' |
| 222 return self.__class__(self) |
| 223 |
| 224 @classmethod |
| 225 def fromkeys(cls, iterable, value=None): |
| 226 '''OD.fromkeys(S[, v]) -> New ordered dictionary with keys from S |
| 227 and values equal to v (which defaults to None). |
| 228 |
| 229 ''' |
| 230 d = cls() |
| 231 for key in iterable: |
| 232 d[key] = value |
| 233 return d |
| 234 |
| 235 def __eq__(self, other): |
| 236 '''od.__eq__(y) <==> od==y. Comparison to another OD is order-sensitive |
| 237 while comparison to a regular mapping is order-insensitive. |
| 238 |
| 239 ''' |
| 240 if isinstance(other, OrderedDict): |
| 241 return len(self)==len(other) and self.items() == other.items() |
| 242 return dict.__eq__(self, other) |
| 243 |
| 244 def __ne__(self, other): |
| 245 return not self == other |
| 246 |
| 247 # -- the following methods are only used in Python 2.7 -- |
| 248 |
| 249 def viewkeys(self): |
| 250 "od.viewkeys() -> a set-like object providing a view on od's keys" |
| 251 return KeysView(self) |
| 252 |
| 253 def viewvalues(self): |
| 254 "od.viewvalues() -> an object providing a view on od's values" |
| 255 return ValuesView(self) |
| 256 |
| 257 def viewitems(self): |
| 258 "od.viewitems() -> a set-like object providing a view on od's items" |
| 259 return ItemsView(self) |
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