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1 # Unmodified from http://code.activestate.com/recipes/576693/ | |
2 # This should be deleted once Py2.7 is available on all bots. | |
Nico
2013/12/13 17:54:18
, http://crbug.com/241769
scottmg
2013/12/13 17:56:29
Done.
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3 # Linked from Python documentation here: | |
4 # http://docs.python.org/2/library/collections.html#collections.OrderedDict | |
5 | |
6 # Backport of OrderedDict() class that runs on Python 2.4, 2.5, 2.6, 2.7 and pyp y. | |
7 # Passes Python2.7's test suite and incorporates all the latest updates. | |
8 | |
9 try: | |
10 from thread import get_ident as _get_ident | |
11 except ImportError: | |
12 from dummy_thread import get_ident as _get_ident | |
13 | |
14 try: | |
15 from _abcoll import KeysView, ValuesView, ItemsView | |
16 except ImportError: | |
17 pass | |
18 | |
19 | |
20 class OrderedDict(dict): | |
21 'Dictionary that remembers insertion order' | |
22 # An inherited dict maps keys to values. | |
23 # The inherited dict provides __getitem__, __len__, __contains__, and get. | |
24 # The remaining methods are order-aware. | |
25 # Big-O running times for all methods are the same as for regular dictionari es. | |
26 | |
27 # The internal self.__map dictionary maps keys to links in a doubly linked l ist. | |
28 # The circular doubly linked list starts and ends with a sentinel element. | |
29 # The sentinel element never gets deleted (this simplifies the algorithm). | |
30 # Each link is stored as a list of length three: [PREV, NEXT, KEY]. | |
31 | |
32 def __init__(self, *args, **kwds): | |
33 '''Initialize an ordered dictionary. Signature is the same as for | |
34 regular dictionaries, but keyword arguments are not recommended | |
35 because their insertion order is arbitrary. | |
36 | |
37 ''' | |
38 if len(args) > 1: | |
39 raise TypeError('expected at most 1 arguments, got %d' % len(args)) | |
40 try: | |
41 self.__root | |
42 except AttributeError: | |
43 self.__root = root = [] # sentinel node | |
44 root[:] = [root, root, None] | |
45 self.__map = {} | |
46 self.__update(*args, **kwds) | |
47 | |
48 def __setitem__(self, key, value, dict_setitem=dict.__setitem__): | |
49 'od.__setitem__(i, y) <==> od[i]=y' | |
50 # Setting a new item creates a new link which goes at the end of the lin ked | |
51 # list, and the inherited dictionary is updated with the new key/value p air. | |
52 if key not in self: | |
53 root = self.__root | |
54 last = root[0] | |
55 last[1] = root[0] = self.__map[key] = [last, root, key] | |
56 dict_setitem(self, key, value) | |
57 | |
58 def __delitem__(self, key, dict_delitem=dict.__delitem__): | |
59 'od.__delitem__(y) <==> del od[y]' | |
60 # Deleting an existing item uses self.__map to find the link which is | |
61 # then removed by updating the links in the predecessor and successor no des. | |
62 dict_delitem(self, key) | |
63 link_prev, link_next, key = self.__map.pop(key) | |
64 link_prev[1] = link_next | |
65 link_next[0] = link_prev | |
66 | |
67 def __iter__(self): | |
68 'od.__iter__() <==> iter(od)' | |
69 root = self.__root | |
70 curr = root[1] | |
71 while curr is not root: | |
72 yield curr[2] | |
73 curr = curr[1] | |
74 | |
75 def __reversed__(self): | |
76 'od.__reversed__() <==> reversed(od)' | |
77 root = self.__root | |
78 curr = root[0] | |
79 while curr is not root: | |
80 yield curr[2] | |
81 curr = curr[0] | |
82 | |
83 def clear(self): | |
84 'od.clear() -> None. Remove all items from od.' | |
85 try: | |
86 for node in self.__map.itervalues(): | |
87 del node[:] | |
88 root = self.__root | |
89 root[:] = [root, root, None] | |
90 self.__map.clear() | |
91 except AttributeError: | |
92 pass | |
93 dict.clear(self) | |
94 | |
95 def popitem(self, last=True): | |
96 '''od.popitem() -> (k, v), return and remove a (key, value) pair. | |
97 Pairs are returned in LIFO order if last is true or FIFO order if false. | |
98 | |
99 ''' | |
100 if not self: | |
101 raise KeyError('dictionary is empty') | |
102 root = self.__root | |
103 if last: | |
104 link = root[0] | |
105 link_prev = link[0] | |
106 link_prev[1] = root | |
107 root[0] = link_prev | |
108 else: | |
109 link = root[1] | |
110 link_next = link[1] | |
111 root[1] = link_next | |
112 link_next[0] = root | |
113 key = link[2] | |
114 del self.__map[key] | |
115 value = dict.pop(self, key) | |
116 return key, value | |
117 | |
118 # -- the following methods do not depend on the internal structure -- | |
119 | |
120 def keys(self): | |
121 'od.keys() -> list of keys in od' | |
122 return list(self) | |
123 | |
124 def values(self): | |
125 'od.values() -> list of values in od' | |
126 return [self[key] for key in self] | |
127 | |
128 def items(self): | |
129 'od.items() -> list of (key, value) pairs in od' | |
130 return [(key, self[key]) for key in self] | |
131 | |
132 def iterkeys(self): | |
133 'od.iterkeys() -> an iterator over the keys in od' | |
134 return iter(self) | |
135 | |
136 def itervalues(self): | |
137 'od.itervalues -> an iterator over the values in od' | |
138 for k in self: | |
139 yield self[k] | |
140 | |
141 def iteritems(self): | |
142 'od.iteritems -> an iterator over the (key, value) items in od' | |
143 for k in self: | |
144 yield (k, self[k]) | |
145 | |
146 def update(*args, **kwds): | |
147 '''od.update(E, **F) -> None. Update od from dict/iterable E and F. | |
148 | |
149 If E is a dict instance, does: for k in E: od[k] = E[k] | |
150 If E has a .keys() method, does: for k in E.keys(): od[k] = E[k] | |
151 Or if E is an iterable of items, does: for k, v in E: od[k] = v | |
152 In either case, this is followed by: for k, v in F.items(): od[k] = v | |
153 | |
154 ''' | |
155 if len(args) > 2: | |
156 raise TypeError('update() takes at most 2 positional ' | |
157 'arguments (%d given)' % (len(args),)) | |
158 elif not args: | |
159 raise TypeError('update() takes at least 1 argument (0 given)') | |
160 self = args[0] | |
161 # Make progressively weaker assumptions about "other" | |
162 other = () | |
163 if len(args) == 2: | |
164 other = args[1] | |
165 if isinstance(other, dict): | |
166 for key in other: | |
167 self[key] = other[key] | |
168 elif hasattr(other, 'keys'): | |
169 for key in other.keys(): | |
170 self[key] = other[key] | |
171 else: | |
172 for key, value in other: | |
173 self[key] = value | |
174 for key, value in kwds.items(): | |
175 self[key] = value | |
176 | |
177 __update = update # let subclasses override update without breaking __init_ _ | |
178 | |
179 __marker = object() | |
180 | |
181 def pop(self, key, default=__marker): | |
182 '''od.pop(k[,d]) -> v, remove specified key and return the corresponding value. | |
183 If key is not found, d is returned if given, otherwise KeyError is raise d. | |
184 | |
185 ''' | |
186 if key in self: | |
187 result = self[key] | |
188 del self[key] | |
189 return result | |
190 if default is self.__marker: | |
191 raise KeyError(key) | |
192 return default | |
193 | |
194 def setdefault(self, key, default=None): | |
195 'od.setdefault(k[,d]) -> od.get(k,d), also set od[k]=d if k not in od' | |
196 if key in self: | |
197 return self[key] | |
198 self[key] = default | |
199 return default | |
200 | |
201 def __repr__(self, _repr_running={}): | |
202 'od.__repr__() <==> repr(od)' | |
203 call_key = id(self), _get_ident() | |
204 if call_key in _repr_running: | |
205 return '...' | |
206 _repr_running[call_key] = 1 | |
207 try: | |
208 if not self: | |
209 return '%s()' % (self.__class__.__name__,) | |
210 return '%s(%r)' % (self.__class__.__name__, self.items()) | |
211 finally: | |
212 del _repr_running[call_key] | |
213 | |
214 def __reduce__(self): | |
215 'Return state information for pickling' | |
216 items = [[k, self[k]] for k in self] | |
217 inst_dict = vars(self).copy() | |
218 for k in vars(OrderedDict()): | |
219 inst_dict.pop(k, None) | |
220 if inst_dict: | |
221 return (self.__class__, (items,), inst_dict) | |
222 return self.__class__, (items,) | |
223 | |
224 def copy(self): | |
225 'od.copy() -> a shallow copy of od' | |
226 return self.__class__(self) | |
227 | |
228 @classmethod | |
229 def fromkeys(cls, iterable, value=None): | |
230 '''OD.fromkeys(S[, v]) -> New ordered dictionary with keys from S | |
231 and values equal to v (which defaults to None). | |
232 | |
233 ''' | |
234 d = cls() | |
235 for key in iterable: | |
236 d[key] = value | |
237 return d | |
238 | |
239 def __eq__(self, other): | |
240 '''od.__eq__(y) <==> od==y. Comparison to another OD is order-sensitive | |
241 while comparison to a regular mapping is order-insensitive. | |
242 | |
243 ''' | |
244 if isinstance(other, OrderedDict): | |
245 return len(self)==len(other) and self.items() == other.items() | |
246 return dict.__eq__(self, other) | |
247 | |
248 def __ne__(self, other): | |
249 return not self == other | |
250 | |
251 # -- the following methods are only used in Python 2.7 -- | |
252 | |
253 def viewkeys(self): | |
254 "od.viewkeys() -> a set-like object providing a view on od's keys" | |
255 return KeysView(self) | |
256 | |
257 def viewvalues(self): | |
258 "od.viewvalues() -> an object providing a view on od's values" | |
259 return ValuesView(self) | |
260 | |
261 def viewitems(self): | |
262 "od.viewitems() -> a set-like object providing a view on od's items" | |
263 return ItemsView(self) | |
264 | |
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