Ben Murdoch | 097c5b2 | 2016-05-18 11:27:45 +0100 | [diff] [blame^] | 1 | # Unmodified from http://code.activestate.com/recipes/576693/ |
| 2 | # other than to add MIT license header (as specified on page, but not in code). |
| 3 | # Linked from Python documentation here: |
| 4 | # http://docs.python.org/2/library/collections.html#collections.OrderedDict |
| 5 | # |
| 6 | # This should be deleted once Py2.7 is available on all bots, see |
| 7 | # http://crbug.com/241769. |
| 8 | # |
| 9 | # Copyright (c) 2009 Raymond Hettinger. |
| 10 | # |
| 11 | # Permission is hereby granted, free of charge, to any person obtaining a copy |
| 12 | # of this software and associated documentation files (the "Software"), to deal |
| 13 | # in the Software without restriction, including without limitation the rights |
| 14 | # to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| 15 | # copies of the Software, and to permit persons to whom the Software is |
| 16 | # furnished to do so, subject to the following conditions: |
| 17 | # |
| 18 | # The above copyright notice and this permission notice shall be included in |
| 19 | # all copies or substantial portions of the Software. |
| 20 | # |
| 21 | # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| 22 | # IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| 23 | # FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| 24 | # AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| 25 | # LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| 26 | # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
| 27 | # THE SOFTWARE. |
| 28 | |
| 29 | # Backport of OrderedDict() class that runs on Python 2.4, 2.5, 2.6, 2.7 and pypy. |
| 30 | # Passes Python2.7's test suite and incorporates all the latest updates. |
| 31 | |
| 32 | try: |
| 33 | from thread import get_ident as _get_ident |
| 34 | except ImportError: |
| 35 | from dummy_thread import get_ident as _get_ident |
| 36 | |
| 37 | try: |
| 38 | from _abcoll import KeysView, ValuesView, ItemsView |
| 39 | except ImportError: |
| 40 | pass |
| 41 | |
| 42 | |
| 43 | class OrderedDict(dict): |
| 44 | 'Dictionary that remembers insertion order' |
| 45 | # An inherited dict maps keys to values. |
| 46 | # The inherited dict provides __getitem__, __len__, __contains__, and get. |
| 47 | # The remaining methods are order-aware. |
| 48 | # Big-O running times for all methods are the same as for regular dictionaries. |
| 49 | |
| 50 | # The internal self.__map dictionary maps keys to links in a doubly linked list. |
| 51 | # The circular doubly linked list starts and ends with a sentinel element. |
| 52 | # The sentinel element never gets deleted (this simplifies the algorithm). |
| 53 | # Each link is stored as a list of length three: [PREV, NEXT, KEY]. |
| 54 | |
| 55 | def __init__(self, *args, **kwds): |
| 56 | '''Initialize an ordered dictionary. Signature is the same as for |
| 57 | regular dictionaries, but keyword arguments are not recommended |
| 58 | because their insertion order is arbitrary. |
| 59 | |
| 60 | ''' |
| 61 | if len(args) > 1: |
| 62 | raise TypeError('expected at most 1 arguments, got %d' % len(args)) |
| 63 | try: |
| 64 | self.__root |
| 65 | except AttributeError: |
| 66 | self.__root = root = [] # sentinel node |
| 67 | root[:] = [root, root, None] |
| 68 | self.__map = {} |
| 69 | self.__update(*args, **kwds) |
| 70 | |
| 71 | def __setitem__(self, key, value, dict_setitem=dict.__setitem__): |
| 72 | 'od.__setitem__(i, y) <==> od[i]=y' |
| 73 | # Setting a new item creates a new link which goes at the end of the linked |
| 74 | # list, and the inherited dictionary is updated with the new key/value pair. |
| 75 | if key not in self: |
| 76 | root = self.__root |
| 77 | last = root[0] |
| 78 | last[1] = root[0] = self.__map[key] = [last, root, key] |
| 79 | dict_setitem(self, key, value) |
| 80 | |
| 81 | def __delitem__(self, key, dict_delitem=dict.__delitem__): |
| 82 | 'od.__delitem__(y) <==> del od[y]' |
| 83 | # Deleting an existing item uses self.__map to find the link which is |
| 84 | # then removed by updating the links in the predecessor and successor nodes. |
| 85 | dict_delitem(self, key) |
| 86 | link_prev, link_next, key = self.__map.pop(key) |
| 87 | link_prev[1] = link_next |
| 88 | link_next[0] = link_prev |
| 89 | |
| 90 | def __iter__(self): |
| 91 | 'od.__iter__() <==> iter(od)' |
| 92 | root = self.__root |
| 93 | curr = root[1] |
| 94 | while curr is not root: |
| 95 | yield curr[2] |
| 96 | curr = curr[1] |
| 97 | |
| 98 | def __reversed__(self): |
| 99 | 'od.__reversed__() <==> reversed(od)' |
| 100 | root = self.__root |
| 101 | curr = root[0] |
| 102 | while curr is not root: |
| 103 | yield curr[2] |
| 104 | curr = curr[0] |
| 105 | |
| 106 | def clear(self): |
| 107 | 'od.clear() -> None. Remove all items from od.' |
| 108 | try: |
| 109 | for node in self.__map.itervalues(): |
| 110 | del node[:] |
| 111 | root = self.__root |
| 112 | root[:] = [root, root, None] |
| 113 | self.__map.clear() |
| 114 | except AttributeError: |
| 115 | pass |
| 116 | dict.clear(self) |
| 117 | |
| 118 | def popitem(self, last=True): |
| 119 | '''od.popitem() -> (k, v), return and remove a (key, value) pair. |
| 120 | Pairs are returned in LIFO order if last is true or FIFO order if false. |
| 121 | |
| 122 | ''' |
| 123 | if not self: |
| 124 | raise KeyError('dictionary is empty') |
| 125 | root = self.__root |
| 126 | if last: |
| 127 | link = root[0] |
| 128 | link_prev = link[0] |
| 129 | link_prev[1] = root |
| 130 | root[0] = link_prev |
| 131 | else: |
| 132 | link = root[1] |
| 133 | link_next = link[1] |
| 134 | root[1] = link_next |
| 135 | link_next[0] = root |
| 136 | key = link[2] |
| 137 | del self.__map[key] |
| 138 | value = dict.pop(self, key) |
| 139 | return key, value |
| 140 | |
| 141 | # -- the following methods do not depend on the internal structure -- |
| 142 | |
| 143 | def keys(self): |
| 144 | 'od.keys() -> list of keys in od' |
| 145 | return list(self) |
| 146 | |
| 147 | def values(self): |
| 148 | 'od.values() -> list of values in od' |
| 149 | return [self[key] for key in self] |
| 150 | |
| 151 | def items(self): |
| 152 | 'od.items() -> list of (key, value) pairs in od' |
| 153 | return [(key, self[key]) for key in self] |
| 154 | |
| 155 | def iterkeys(self): |
| 156 | 'od.iterkeys() -> an iterator over the keys in od' |
| 157 | return iter(self) |
| 158 | |
| 159 | def itervalues(self): |
| 160 | 'od.itervalues -> an iterator over the values in od' |
| 161 | for k in self: |
| 162 | yield self[k] |
| 163 | |
| 164 | def iteritems(self): |
| 165 | 'od.iteritems -> an iterator over the (key, value) items in od' |
| 166 | for k in self: |
| 167 | yield (k, self[k]) |
| 168 | |
| 169 | # Suppress 'OrderedDict.update: Method has no argument': |
| 170 | # pylint: disable=E0211 |
| 171 | def update(*args, **kwds): |
| 172 | '''od.update(E, **F) -> None. Update od from dict/iterable E and F. |
| 173 | |
| 174 | If E is a dict instance, does: for k in E: od[k] = E[k] |
| 175 | If E has a .keys() method, does: for k in E.keys(): od[k] = E[k] |
| 176 | Or if E is an iterable of items, does: for k, v in E: od[k] = v |
| 177 | In either case, this is followed by: for k, v in F.items(): od[k] = v |
| 178 | |
| 179 | ''' |
| 180 | if len(args) > 2: |
| 181 | raise TypeError('update() takes at most 2 positional ' |
| 182 | 'arguments (%d given)' % (len(args),)) |
| 183 | elif not args: |
| 184 | raise TypeError('update() takes at least 1 argument (0 given)') |
| 185 | self = args[0] |
| 186 | # Make progressively weaker assumptions about "other" |
| 187 | other = () |
| 188 | if len(args) == 2: |
| 189 | other = args[1] |
| 190 | if isinstance(other, dict): |
| 191 | for key in other: |
| 192 | self[key] = other[key] |
| 193 | elif hasattr(other, 'keys'): |
| 194 | for key in other.keys(): |
| 195 | self[key] = other[key] |
| 196 | else: |
| 197 | for key, value in other: |
| 198 | self[key] = value |
| 199 | for key, value in kwds.items(): |
| 200 | self[key] = value |
| 201 | |
| 202 | __update = update # let subclasses override update without breaking __init__ |
| 203 | |
| 204 | __marker = object() |
| 205 | |
| 206 | def pop(self, key, default=__marker): |
| 207 | '''od.pop(k[,d]) -> v, remove specified key and return the corresponding value. |
| 208 | If key is not found, d is returned if given, otherwise KeyError is raised. |
| 209 | |
| 210 | ''' |
| 211 | if key in self: |
| 212 | result = self[key] |
| 213 | del self[key] |
| 214 | return result |
| 215 | if default is self.__marker: |
| 216 | raise KeyError(key) |
| 217 | return default |
| 218 | |
| 219 | def setdefault(self, key, default=None): |
| 220 | 'od.setdefault(k[,d]) -> od.get(k,d), also set od[k]=d if k not in od' |
| 221 | if key in self: |
| 222 | return self[key] |
| 223 | self[key] = default |
| 224 | return default |
| 225 | |
| 226 | def __repr__(self, _repr_running={}): |
| 227 | 'od.__repr__() <==> repr(od)' |
| 228 | call_key = id(self), _get_ident() |
| 229 | if call_key in _repr_running: |
| 230 | return '...' |
| 231 | _repr_running[call_key] = 1 |
| 232 | try: |
| 233 | if not self: |
| 234 | return '%s()' % (self.__class__.__name__,) |
| 235 | return '%s(%r)' % (self.__class__.__name__, self.items()) |
| 236 | finally: |
| 237 | del _repr_running[call_key] |
| 238 | |
| 239 | def __reduce__(self): |
| 240 | 'Return state information for pickling' |
| 241 | items = [[k, self[k]] for k in self] |
| 242 | inst_dict = vars(self).copy() |
| 243 | for k in vars(OrderedDict()): |
| 244 | inst_dict.pop(k, None) |
| 245 | if inst_dict: |
| 246 | return (self.__class__, (items,), inst_dict) |
| 247 | return self.__class__, (items,) |
| 248 | |
| 249 | def copy(self): |
| 250 | 'od.copy() -> a shallow copy of od' |
| 251 | return self.__class__(self) |
| 252 | |
| 253 | @classmethod |
| 254 | def fromkeys(cls, iterable, value=None): |
| 255 | '''OD.fromkeys(S[, v]) -> New ordered dictionary with keys from S |
| 256 | and values equal to v (which defaults to None). |
| 257 | |
| 258 | ''' |
| 259 | d = cls() |
| 260 | for key in iterable: |
| 261 | d[key] = value |
| 262 | return d |
| 263 | |
| 264 | def __eq__(self, other): |
| 265 | '''od.__eq__(y) <==> od==y. Comparison to another OD is order-sensitive |
| 266 | while comparison to a regular mapping is order-insensitive. |
| 267 | |
| 268 | ''' |
| 269 | if isinstance(other, OrderedDict): |
| 270 | return len(self)==len(other) and self.items() == other.items() |
| 271 | return dict.__eq__(self, other) |
| 272 | |
| 273 | def __ne__(self, other): |
| 274 | return not self == other |
| 275 | |
| 276 | # -- the following methods are only used in Python 2.7 -- |
| 277 | |
| 278 | def viewkeys(self): |
| 279 | "od.viewkeys() -> a set-like object providing a view on od's keys" |
| 280 | return KeysView(self) |
| 281 | |
| 282 | def viewvalues(self): |
| 283 | "od.viewvalues() -> an object providing a view on od's values" |
| 284 | return ValuesView(self) |
| 285 | |
| 286 | def viewitems(self): |
| 287 | "od.viewitems() -> a set-like object providing a view on od's items" |
| 288 | return ItemsView(self) |
| 289 | |