Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 1 | # Copyright 2007 Google, Inc. All Rights Reserved. |
| 2 | # Licensed to PSF under a Contributor Agreement. |
| 3 | |
| 4 | """Abstract Base Classes (ABCs) for collections, according to PEP 3119. |
| 5 | |
Raymond Hettinger | 158c9c2 | 2011-02-22 00:41:50 +0000 | [diff] [blame] | 6 | Unit tests are in test_collections. |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 7 | """ |
| 8 | |
| 9 | from abc import ABCMeta, abstractmethod |
Benjamin Peterson | 4118174 | 2008-07-02 20:22:54 +0000 | [diff] [blame] | 10 | import sys |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 11 | |
| 12 | __all__ = ["Hashable", "Iterable", "Iterator", |
| 13 | "Sized", "Container", "Callable", |
| 14 | "Set", "MutableSet", |
| 15 | "Mapping", "MutableMapping", |
| 16 | "MappingView", "KeysView", "ItemsView", "ValuesView", |
| 17 | "Sequence", "MutableSequence", |
Guido van Rossum | d05eb00 | 2007-11-21 22:26:24 +0000 | [diff] [blame] | 18 | "ByteString", |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 19 | ] |
| 20 | |
Christian Heimes | bf235bd | 2013-10-13 02:21:33 +0200 | [diff] [blame] | 21 | # This module has been renamed from collections.abc to _collections_abc to |
| 22 | # speed up interpreter startup. Some of the types such as MutableMapping are |
| 23 | # required early but collections module imports a lot of other modules. |
| 24 | # See issue #19218 |
| 25 | __name__ = "collections.abc" |
| 26 | |
Raymond Hettinger | 0218428 | 2012-04-05 13:31:12 -0700 | [diff] [blame] | 27 | # Private list of types that we want to register with the various ABCs |
| 28 | # so that they will pass tests like: |
| 29 | # it = iter(somebytearray) |
| 30 | # assert isinstance(it, Iterable) |
| 31 | # Note: in other implementations, these types many not be distinct |
| 32 | # and they make have their own implementation specific types that |
| 33 | # are not included on this list. |
Christian Heimes | f83be4e | 2007-11-28 09:44:38 +0000 | [diff] [blame] | 34 | bytes_iterator = type(iter(b'')) |
| 35 | bytearray_iterator = type(iter(bytearray())) |
| 36 | #callable_iterator = ??? |
| 37 | dict_keyiterator = type(iter({}.keys())) |
| 38 | dict_valueiterator = type(iter({}.values())) |
| 39 | dict_itemiterator = type(iter({}.items())) |
| 40 | list_iterator = type(iter([])) |
| 41 | list_reverseiterator = type(iter(reversed([]))) |
| 42 | range_iterator = type(iter(range(0))) |
| 43 | set_iterator = type(iter(set())) |
| 44 | str_iterator = type(iter("")) |
| 45 | tuple_iterator = type(iter(())) |
| 46 | zip_iterator = type(iter(zip())) |
| 47 | ## views ## |
| 48 | dict_keys = type({}.keys()) |
| 49 | dict_values = type({}.values()) |
| 50 | dict_items = type({}.items()) |
Christian Heimes | 0db3853 | 2007-11-29 16:21:13 +0000 | [diff] [blame] | 51 | ## misc ## |
Victor Stinner | 7b17a4e | 2012-04-20 01:41:36 +0200 | [diff] [blame] | 52 | mappingproxy = type(type.__dict__) |
Christian Heimes | f83be4e | 2007-11-28 09:44:38 +0000 | [diff] [blame] | 53 | |
| 54 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 55 | ### ONE-TRICK PONIES ### |
| 56 | |
| 57 | class Hashable(metaclass=ABCMeta): |
| 58 | |
Raymond Hettinger | c46759a | 2011-03-22 11:46:25 -0700 | [diff] [blame] | 59 | __slots__ = () |
| 60 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 61 | @abstractmethod |
| 62 | def __hash__(self): |
| 63 | return 0 |
| 64 | |
| 65 | @classmethod |
| 66 | def __subclasshook__(cls, C): |
| 67 | if cls is Hashable: |
| 68 | for B in C.__mro__: |
| 69 | if "__hash__" in B.__dict__: |
| 70 | if B.__dict__["__hash__"]: |
| 71 | return True |
| 72 | break |
| 73 | return NotImplemented |
| 74 | |
| 75 | |
| 76 | class Iterable(metaclass=ABCMeta): |
| 77 | |
Raymond Hettinger | c46759a | 2011-03-22 11:46:25 -0700 | [diff] [blame] | 78 | __slots__ = () |
| 79 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 80 | @abstractmethod |
| 81 | def __iter__(self): |
| 82 | while False: |
| 83 | yield None |
| 84 | |
| 85 | @classmethod |
| 86 | def __subclasshook__(cls, C): |
| 87 | if cls is Iterable: |
| 88 | if any("__iter__" in B.__dict__ for B in C.__mro__): |
| 89 | return True |
| 90 | return NotImplemented |
| 91 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 92 | |
Raymond Hettinger | 74b6495 | 2008-02-09 02:53:48 +0000 | [diff] [blame] | 93 | class Iterator(Iterable): |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 94 | |
Raymond Hettinger | c46759a | 2011-03-22 11:46:25 -0700 | [diff] [blame] | 95 | __slots__ = () |
| 96 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 97 | @abstractmethod |
| 98 | def __next__(self): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 99 | 'Return the next item from the iterator. When exhausted, raise StopIteration' |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 100 | raise StopIteration |
| 101 | |
| 102 | def __iter__(self): |
| 103 | return self |
| 104 | |
| 105 | @classmethod |
| 106 | def __subclasshook__(cls, C): |
| 107 | if cls is Iterator: |
Raymond Hettinger | ead2222 | 2010-11-29 03:56:12 +0000 | [diff] [blame] | 108 | if (any("__next__" in B.__dict__ for B in C.__mro__) and |
| 109 | any("__iter__" in B.__dict__ for B in C.__mro__)): |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 110 | return True |
| 111 | return NotImplemented |
| 112 | |
Christian Heimes | f83be4e | 2007-11-28 09:44:38 +0000 | [diff] [blame] | 113 | Iterator.register(bytes_iterator) |
| 114 | Iterator.register(bytearray_iterator) |
| 115 | #Iterator.register(callable_iterator) |
| 116 | Iterator.register(dict_keyiterator) |
| 117 | Iterator.register(dict_valueiterator) |
| 118 | Iterator.register(dict_itemiterator) |
| 119 | Iterator.register(list_iterator) |
| 120 | Iterator.register(list_reverseiterator) |
| 121 | Iterator.register(range_iterator) |
| 122 | Iterator.register(set_iterator) |
| 123 | Iterator.register(str_iterator) |
| 124 | Iterator.register(tuple_iterator) |
| 125 | Iterator.register(zip_iterator) |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 126 | |
| 127 | class Sized(metaclass=ABCMeta): |
| 128 | |
Raymond Hettinger | c46759a | 2011-03-22 11:46:25 -0700 | [diff] [blame] | 129 | __slots__ = () |
| 130 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 131 | @abstractmethod |
| 132 | def __len__(self): |
| 133 | return 0 |
| 134 | |
| 135 | @classmethod |
| 136 | def __subclasshook__(cls, C): |
| 137 | if cls is Sized: |
| 138 | if any("__len__" in B.__dict__ for B in C.__mro__): |
| 139 | return True |
| 140 | return NotImplemented |
| 141 | |
| 142 | |
| 143 | class Container(metaclass=ABCMeta): |
| 144 | |
Raymond Hettinger | c46759a | 2011-03-22 11:46:25 -0700 | [diff] [blame] | 145 | __slots__ = () |
| 146 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 147 | @abstractmethod |
| 148 | def __contains__(self, x): |
| 149 | return False |
| 150 | |
| 151 | @classmethod |
| 152 | def __subclasshook__(cls, C): |
| 153 | if cls is Container: |
| 154 | if any("__contains__" in B.__dict__ for B in C.__mro__): |
| 155 | return True |
| 156 | return NotImplemented |
| 157 | |
| 158 | |
| 159 | class Callable(metaclass=ABCMeta): |
| 160 | |
Raymond Hettinger | c46759a | 2011-03-22 11:46:25 -0700 | [diff] [blame] | 161 | __slots__ = () |
| 162 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 163 | @abstractmethod |
Christian Heimes | 7864476 | 2008-03-04 23:39:23 +0000 | [diff] [blame] | 164 | def __call__(self, *args, **kwds): |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 165 | return False |
| 166 | |
| 167 | @classmethod |
| 168 | def __subclasshook__(cls, C): |
| 169 | if cls is Callable: |
| 170 | if any("__call__" in B.__dict__ for B in C.__mro__): |
| 171 | return True |
| 172 | return NotImplemented |
| 173 | |
| 174 | |
| 175 | ### SETS ### |
| 176 | |
| 177 | |
Raymond Hettinger | 74b6495 | 2008-02-09 02:53:48 +0000 | [diff] [blame] | 178 | class Set(Sized, Iterable, Container): |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 179 | |
| 180 | """A set is a finite, iterable container. |
| 181 | |
| 182 | This class provides concrete generic implementations of all |
| 183 | methods except for __contains__, __iter__ and __len__. |
| 184 | |
| 185 | To override the comparisons (presumably for speed, as the |
| 186 | semantics are fixed), all you have to do is redefine __le__ and |
| 187 | then the other operations will automatically follow suit. |
| 188 | """ |
| 189 | |
Raymond Hettinger | c46759a | 2011-03-22 11:46:25 -0700 | [diff] [blame] | 190 | __slots__ = () |
| 191 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 192 | def __le__(self, other): |
| 193 | if not isinstance(other, Set): |
| 194 | return NotImplemented |
| 195 | if len(self) > len(other): |
| 196 | return False |
| 197 | for elem in self: |
| 198 | if elem not in other: |
| 199 | return False |
| 200 | return True |
| 201 | |
| 202 | def __lt__(self, other): |
| 203 | if not isinstance(other, Set): |
| 204 | return NotImplemented |
| 205 | return len(self) < len(other) and self.__le__(other) |
| 206 | |
Raymond Hettinger | 7190942 | 2008-02-09 00:08:16 +0000 | [diff] [blame] | 207 | def __gt__(self, other): |
| 208 | if not isinstance(other, Set): |
| 209 | return NotImplemented |
Andrew Svetlov | bcac6ad | 2012-11-01 13:28:54 +0200 | [diff] [blame] | 210 | return other.__lt__(self) |
Raymond Hettinger | 7190942 | 2008-02-09 00:08:16 +0000 | [diff] [blame] | 211 | |
| 212 | def __ge__(self, other): |
| 213 | if not isinstance(other, Set): |
| 214 | return NotImplemented |
Andrew Svetlov | bcac6ad | 2012-11-01 13:28:54 +0200 | [diff] [blame] | 215 | return other.__le__(self) |
Raymond Hettinger | 7190942 | 2008-02-09 00:08:16 +0000 | [diff] [blame] | 216 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 217 | def __eq__(self, other): |
| 218 | if not isinstance(other, Set): |
| 219 | return NotImplemented |
| 220 | return len(self) == len(other) and self.__le__(other) |
| 221 | |
Raymond Hettinger | 7190942 | 2008-02-09 00:08:16 +0000 | [diff] [blame] | 222 | def __ne__(self, other): |
| 223 | return not (self == other) |
| 224 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 225 | @classmethod |
| 226 | def _from_iterable(cls, it): |
Raymond Hettinger | 8284c4a | 2008-02-06 20:47:09 +0000 | [diff] [blame] | 227 | '''Construct an instance of the class from any iterable input. |
| 228 | |
| 229 | Must override this method if the class constructor signature |
Raymond Hettinger | 7aebb64 | 2008-02-09 03:25:08 +0000 | [diff] [blame] | 230 | does not accept an iterable for an input. |
Raymond Hettinger | 8284c4a | 2008-02-06 20:47:09 +0000 | [diff] [blame] | 231 | ''' |
Raymond Hettinger | 7aebb64 | 2008-02-09 03:25:08 +0000 | [diff] [blame] | 232 | return cls(it) |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 233 | |
| 234 | def __and__(self, other): |
| 235 | if not isinstance(other, Iterable): |
| 236 | return NotImplemented |
| 237 | return self._from_iterable(value for value in other if value in self) |
| 238 | |
Christian Heimes | 190d79e | 2008-01-30 11:58:22 +0000 | [diff] [blame] | 239 | def isdisjoint(self, other): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 240 | 'Return True if two sets have a null intersection.' |
Christian Heimes | 190d79e | 2008-01-30 11:58:22 +0000 | [diff] [blame] | 241 | for value in other: |
| 242 | if value in self: |
| 243 | return False |
| 244 | return True |
| 245 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 246 | def __or__(self, other): |
| 247 | if not isinstance(other, Iterable): |
| 248 | return NotImplemented |
Christian Heimes | 7864476 | 2008-03-04 23:39:23 +0000 | [diff] [blame] | 249 | chain = (e for s in (self, other) for e in s) |
| 250 | return self._from_iterable(chain) |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 251 | |
| 252 | def __sub__(self, other): |
| 253 | if not isinstance(other, Set): |
| 254 | if not isinstance(other, Iterable): |
| 255 | return NotImplemented |
| 256 | other = self._from_iterable(other) |
| 257 | return self._from_iterable(value for value in self |
| 258 | if value not in other) |
| 259 | |
| 260 | def __xor__(self, other): |
| 261 | if not isinstance(other, Set): |
| 262 | if not isinstance(other, Iterable): |
| 263 | return NotImplemented |
| 264 | other = self._from_iterable(other) |
| 265 | return (self - other) | (other - self) |
| 266 | |
| 267 | def _hash(self): |
| 268 | """Compute the hash value of a set. |
| 269 | |
| 270 | Note that we don't define __hash__: not all sets are hashable. |
| 271 | But if you define a hashable set type, its __hash__ should |
| 272 | call this function. |
| 273 | |
| 274 | This must be compatible __eq__. |
| 275 | |
| 276 | All sets ought to compare equal if they contain the same |
| 277 | elements, regardless of how they are implemented, and |
| 278 | regardless of the order of the elements; so there's not much |
| 279 | freedom for __eq__ or __hash__. We match the algorithm used |
| 280 | by the built-in frozenset type. |
| 281 | """ |
Christian Heimes | a37d4c6 | 2007-12-04 23:02:19 +0000 | [diff] [blame] | 282 | MAX = sys.maxsize |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 283 | MASK = 2 * MAX + 1 |
| 284 | n = len(self) |
| 285 | h = 1927868237 * (n + 1) |
| 286 | h &= MASK |
| 287 | for x in self: |
| 288 | hx = hash(x) |
| 289 | h ^= (hx ^ (hx << 16) ^ 89869747) * 3644798167 |
| 290 | h &= MASK |
| 291 | h = h * 69069 + 907133923 |
| 292 | h &= MASK |
| 293 | if h > MAX: |
| 294 | h -= MASK + 1 |
| 295 | if h == -1: |
| 296 | h = 590923713 |
| 297 | return h |
| 298 | |
| 299 | Set.register(frozenset) |
| 300 | |
| 301 | |
| 302 | class MutableSet(Set): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 303 | """A mutable set is a finite, iterable container. |
| 304 | |
| 305 | This class provides concrete generic implementations of all |
| 306 | methods except for __contains__, __iter__, __len__, |
| 307 | add(), and discard(). |
| 308 | |
| 309 | To override the comparisons (presumably for speed, as the |
| 310 | semantics are fixed), all you have to do is redefine __le__ and |
| 311 | then the other operations will automatically follow suit. |
| 312 | """ |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 313 | |
Raymond Hettinger | c46759a | 2011-03-22 11:46:25 -0700 | [diff] [blame] | 314 | __slots__ = () |
| 315 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 316 | @abstractmethod |
| 317 | def add(self, value): |
Benjamin Peterson | 058e31e | 2009-01-16 03:54:08 +0000 | [diff] [blame] | 318 | """Add an element.""" |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 319 | raise NotImplementedError |
| 320 | |
| 321 | @abstractmethod |
| 322 | def discard(self, value): |
Benjamin Peterson | 058e31e | 2009-01-16 03:54:08 +0000 | [diff] [blame] | 323 | """Remove an element. Do not raise an exception if absent.""" |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 324 | raise NotImplementedError |
| 325 | |
Christian Heimes | 190d79e | 2008-01-30 11:58:22 +0000 | [diff] [blame] | 326 | def remove(self, value): |
| 327 | """Remove an element. If not a member, raise a KeyError.""" |
| 328 | if value not in self: |
| 329 | raise KeyError(value) |
| 330 | self.discard(value) |
| 331 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 332 | def pop(self): |
| 333 | """Return the popped value. Raise KeyError if empty.""" |
| 334 | it = iter(self) |
| 335 | try: |
Raymond Hettinger | ae65018 | 2009-01-28 23:33:59 +0000 | [diff] [blame] | 336 | value = next(it) |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 337 | except StopIteration: |
| 338 | raise KeyError |
| 339 | self.discard(value) |
| 340 | return value |
| 341 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 342 | def clear(self): |
| 343 | """This is slow (creates N new iterators!) but effective.""" |
| 344 | try: |
| 345 | while True: |
| 346 | self.pop() |
| 347 | except KeyError: |
| 348 | pass |
| 349 | |
Raymond Hettinger | b3d89a4 | 2011-01-12 20:37:47 +0000 | [diff] [blame] | 350 | def __ior__(self, it): |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 351 | for value in it: |
| 352 | self.add(value) |
| 353 | return self |
| 354 | |
Raymond Hettinger | b3d89a4 | 2011-01-12 20:37:47 +0000 | [diff] [blame] | 355 | def __iand__(self, it): |
Raymond Hettinger | 3f10a95 | 2009-04-01 19:05:50 +0000 | [diff] [blame] | 356 | for value in (self - it): |
| 357 | self.discard(value) |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 358 | return self |
| 359 | |
Raymond Hettinger | b3d89a4 | 2011-01-12 20:37:47 +0000 | [diff] [blame] | 360 | def __ixor__(self, it): |
Daniel Stutzbach | 31da5b2 | 2010-08-24 20:49:57 +0000 | [diff] [blame] | 361 | if it is self: |
| 362 | self.clear() |
| 363 | else: |
| 364 | if not isinstance(it, Set): |
| 365 | it = self._from_iterable(it) |
| 366 | for value in it: |
| 367 | if value in self: |
| 368 | self.discard(value) |
| 369 | else: |
| 370 | self.add(value) |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 371 | return self |
| 372 | |
Raymond Hettinger | b3d89a4 | 2011-01-12 20:37:47 +0000 | [diff] [blame] | 373 | def __isub__(self, it): |
Daniel Stutzbach | 31da5b2 | 2010-08-24 20:49:57 +0000 | [diff] [blame] | 374 | if it is self: |
| 375 | self.clear() |
| 376 | else: |
| 377 | for value in it: |
| 378 | self.discard(value) |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 379 | return self |
| 380 | |
| 381 | MutableSet.register(set) |
| 382 | |
| 383 | |
| 384 | ### MAPPINGS ### |
| 385 | |
| 386 | |
Raymond Hettinger | 74b6495 | 2008-02-09 02:53:48 +0000 | [diff] [blame] | 387 | class Mapping(Sized, Iterable, Container): |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 388 | |
Raymond Hettinger | c46759a | 2011-03-22 11:46:25 -0700 | [diff] [blame] | 389 | __slots__ = () |
| 390 | |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 391 | """A Mapping is a generic container for associating key/value |
| 392 | pairs. |
| 393 | |
| 394 | This class provides concrete generic implementations of all |
| 395 | methods except for __getitem__, __iter__, and __len__. |
| 396 | |
| 397 | """ |
| 398 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 399 | @abstractmethod |
| 400 | def __getitem__(self, key): |
| 401 | raise KeyError |
| 402 | |
| 403 | def get(self, key, default=None): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 404 | 'D.get(k[,d]) -> D[k] if k in D, else d. d defaults to None.' |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 405 | try: |
| 406 | return self[key] |
| 407 | except KeyError: |
| 408 | return default |
| 409 | |
| 410 | def __contains__(self, key): |
| 411 | try: |
| 412 | self[key] |
| 413 | except KeyError: |
| 414 | return False |
| 415 | else: |
| 416 | return True |
| 417 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 418 | def keys(self): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 419 | "D.keys() -> a set-like object providing a view on D's keys" |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 420 | return KeysView(self) |
| 421 | |
| 422 | def items(self): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 423 | "D.items() -> a set-like object providing a view on D's items" |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 424 | return ItemsView(self) |
| 425 | |
| 426 | def values(self): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 427 | "D.values() -> an object providing a view on D's values" |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 428 | return ValuesView(self) |
| 429 | |
Raymond Hettinger | b9da9bc | 2008-02-04 20:44:31 +0000 | [diff] [blame] | 430 | def __eq__(self, other): |
Benjamin Peterson | 4ad6bd5 | 2010-05-21 20:55:22 +0000 | [diff] [blame] | 431 | if not isinstance(other, Mapping): |
| 432 | return NotImplemented |
| 433 | return dict(self.items()) == dict(other.items()) |
Raymond Hettinger | b9da9bc | 2008-02-04 20:44:31 +0000 | [diff] [blame] | 434 | |
| 435 | def __ne__(self, other): |
Raymond Hettinger | 554c8b8 | 2008-02-05 22:54:43 +0000 | [diff] [blame] | 436 | return not (self == other) |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 437 | |
Victor Stinner | 7b17a4e | 2012-04-20 01:41:36 +0200 | [diff] [blame] | 438 | Mapping.register(mappingproxy) |
| 439 | |
Christian Heimes | 2202f87 | 2008-02-06 14:31:34 +0000 | [diff] [blame] | 440 | |
Raymond Hettinger | bfd0612 | 2008-02-09 10:04:32 +0000 | [diff] [blame] | 441 | class MappingView(Sized): |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 442 | |
| 443 | def __init__(self, mapping): |
| 444 | self._mapping = mapping |
| 445 | |
| 446 | def __len__(self): |
| 447 | return len(self._mapping) |
| 448 | |
Raymond Hettinger | 89fc2b7 | 2009-02-27 07:47:32 +0000 | [diff] [blame] | 449 | def __repr__(self): |
| 450 | return '{0.__class__.__name__}({0._mapping!r})'.format(self) |
| 451 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 452 | |
| 453 | class KeysView(MappingView, Set): |
| 454 | |
Raymond Hettinger | 9117c75 | 2010-08-22 07:44:24 +0000 | [diff] [blame] | 455 | @classmethod |
| 456 | def _from_iterable(self, it): |
| 457 | return set(it) |
| 458 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 459 | def __contains__(self, key): |
| 460 | return key in self._mapping |
| 461 | |
| 462 | def __iter__(self): |
Philip Jenvey | 4993cc0 | 2012-10-01 12:53:43 -0700 | [diff] [blame] | 463 | yield from self._mapping |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 464 | |
Christian Heimes | f83be4e | 2007-11-28 09:44:38 +0000 | [diff] [blame] | 465 | KeysView.register(dict_keys) |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 466 | |
| 467 | |
| 468 | class ItemsView(MappingView, Set): |
| 469 | |
Raymond Hettinger | 9117c75 | 2010-08-22 07:44:24 +0000 | [diff] [blame] | 470 | @classmethod |
| 471 | def _from_iterable(self, it): |
| 472 | return set(it) |
| 473 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 474 | def __contains__(self, item): |
| 475 | key, value = item |
| 476 | try: |
| 477 | v = self._mapping[key] |
| 478 | except KeyError: |
| 479 | return False |
| 480 | else: |
| 481 | return v == value |
| 482 | |
| 483 | def __iter__(self): |
| 484 | for key in self._mapping: |
| 485 | yield (key, self._mapping[key]) |
| 486 | |
Christian Heimes | f83be4e | 2007-11-28 09:44:38 +0000 | [diff] [blame] | 487 | ItemsView.register(dict_items) |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 488 | |
| 489 | |
| 490 | class ValuesView(MappingView): |
| 491 | |
| 492 | def __contains__(self, value): |
| 493 | for key in self._mapping: |
| 494 | if value == self._mapping[key]: |
| 495 | return True |
| 496 | return False |
| 497 | |
| 498 | def __iter__(self): |
| 499 | for key in self._mapping: |
| 500 | yield self._mapping[key] |
| 501 | |
Christian Heimes | f83be4e | 2007-11-28 09:44:38 +0000 | [diff] [blame] | 502 | ValuesView.register(dict_values) |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 503 | |
| 504 | |
| 505 | class MutableMapping(Mapping): |
| 506 | |
Raymond Hettinger | c46759a | 2011-03-22 11:46:25 -0700 | [diff] [blame] | 507 | __slots__ = () |
| 508 | |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 509 | """A MutableMapping is a generic container for associating |
| 510 | key/value pairs. |
| 511 | |
| 512 | This class provides concrete generic implementations of all |
| 513 | methods except for __getitem__, __setitem__, __delitem__, |
| 514 | __iter__, and __len__. |
| 515 | |
| 516 | """ |
| 517 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 518 | @abstractmethod |
| 519 | def __setitem__(self, key, value): |
| 520 | raise KeyError |
| 521 | |
| 522 | @abstractmethod |
| 523 | def __delitem__(self, key): |
| 524 | raise KeyError |
| 525 | |
| 526 | __marker = object() |
| 527 | |
| 528 | def pop(self, key, default=__marker): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 529 | '''D.pop(k[,d]) -> v, remove specified key and return the corresponding value. |
| 530 | If key is not found, d is returned if given, otherwise KeyError is raised. |
| 531 | ''' |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 532 | try: |
| 533 | value = self[key] |
| 534 | except KeyError: |
| 535 | if default is self.__marker: |
| 536 | raise |
| 537 | return default |
| 538 | else: |
| 539 | del self[key] |
| 540 | return value |
| 541 | |
| 542 | def popitem(self): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 543 | '''D.popitem() -> (k, v), remove and return some (key, value) pair |
| 544 | as a 2-tuple; but raise KeyError if D is empty. |
| 545 | ''' |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 546 | try: |
| 547 | key = next(iter(self)) |
| 548 | except StopIteration: |
| 549 | raise KeyError |
| 550 | value = self[key] |
| 551 | del self[key] |
| 552 | return key, value |
| 553 | |
| 554 | def clear(self): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 555 | 'D.clear() -> None. Remove all items from D.' |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 556 | try: |
| 557 | while True: |
| 558 | self.popitem() |
| 559 | except KeyError: |
| 560 | pass |
| 561 | |
Mark Dickinson | b214e90 | 2010-07-11 18:53:06 +0000 | [diff] [blame] | 562 | def update(*args, **kwds): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 563 | ''' D.update([E, ]**F) -> None. Update D from mapping/iterable E and F. |
| 564 | If E present and has a .keys() method, does: for k in E: D[k] = E[k] |
| 565 | If E present and lacks .keys() method, does: for (k, v) in E: D[k] = v |
| 566 | In either case, this is followed by: for k, v in F.items(): D[k] = v |
| 567 | ''' |
Mark Dickinson | b214e90 | 2010-07-11 18:53:06 +0000 | [diff] [blame] | 568 | if len(args) > 2: |
| 569 | raise TypeError("update() takes at most 2 positional " |
| 570 | "arguments ({} given)".format(len(args))) |
| 571 | elif not args: |
| 572 | raise TypeError("update() takes at least 1 argument (0 given)") |
| 573 | self = args[0] |
| 574 | other = args[1] if len(args) >= 2 else () |
| 575 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 576 | if isinstance(other, Mapping): |
| 577 | for key in other: |
| 578 | self[key] = other[key] |
| 579 | elif hasattr(other, "keys"): |
| 580 | for key in other.keys(): |
| 581 | self[key] = other[key] |
| 582 | else: |
| 583 | for key, value in other: |
| 584 | self[key] = value |
| 585 | for key, value in kwds.items(): |
| 586 | self[key] = value |
| 587 | |
Raymond Hettinger | b9da9bc | 2008-02-04 20:44:31 +0000 | [diff] [blame] | 588 | def setdefault(self, key, default=None): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 589 | 'D.setdefault(k[,d]) -> D.get(k,d), also set D[k]=d if k not in D' |
Raymond Hettinger | b9da9bc | 2008-02-04 20:44:31 +0000 | [diff] [blame] | 590 | try: |
| 591 | return self[key] |
| 592 | except KeyError: |
| 593 | self[key] = default |
| 594 | return default |
| 595 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 596 | MutableMapping.register(dict) |
| 597 | |
| 598 | |
| 599 | ### SEQUENCES ### |
| 600 | |
| 601 | |
Raymond Hettinger | 74b6495 | 2008-02-09 02:53:48 +0000 | [diff] [blame] | 602 | class Sequence(Sized, Iterable, Container): |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 603 | |
| 604 | """All the operations on a read-only sequence. |
| 605 | |
| 606 | Concrete subclasses must override __new__ or __init__, |
| 607 | __getitem__, and __len__. |
| 608 | """ |
| 609 | |
Raymond Hettinger | c46759a | 2011-03-22 11:46:25 -0700 | [diff] [blame] | 610 | __slots__ = () |
| 611 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 612 | @abstractmethod |
| 613 | def __getitem__(self, index): |
| 614 | raise IndexError |
| 615 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 616 | def __iter__(self): |
| 617 | i = 0 |
Raymond Hettinger | 7190942 | 2008-02-09 00:08:16 +0000 | [diff] [blame] | 618 | try: |
| 619 | while True: |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 620 | v = self[i] |
Raymond Hettinger | 7190942 | 2008-02-09 00:08:16 +0000 | [diff] [blame] | 621 | yield v |
| 622 | i += 1 |
| 623 | except IndexError: |
| 624 | return |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 625 | |
| 626 | def __contains__(self, value): |
| 627 | for v in self: |
| 628 | if v == value: |
| 629 | return True |
| 630 | return False |
| 631 | |
| 632 | def __reversed__(self): |
| 633 | for i in reversed(range(len(self))): |
| 634 | yield self[i] |
| 635 | |
| 636 | def index(self, value): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 637 | '''S.index(value) -> integer -- return first index of value. |
| 638 | Raises ValueError if the value is not present. |
| 639 | ''' |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 640 | for i, v in enumerate(self): |
| 641 | if v == value: |
| 642 | return i |
| 643 | raise ValueError |
| 644 | |
| 645 | def count(self, value): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 646 | 'S.count(value) -> integer -- return number of occurrences of value' |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 647 | return sum(1 for v in self if v == value) |
| 648 | |
| 649 | Sequence.register(tuple) |
Guido van Rossum | 3172c5d | 2007-10-16 18:12:55 +0000 | [diff] [blame] | 650 | Sequence.register(str) |
Raymond Hettinger | 9aa53c2 | 2009-02-24 11:25:35 +0000 | [diff] [blame] | 651 | Sequence.register(range) |
Nick Coghlan | 45163cc | 2013-10-02 22:31:47 +1000 | [diff] [blame] | 652 | Sequence.register(memoryview) |
Guido van Rossum | d05eb00 | 2007-11-21 22:26:24 +0000 | [diff] [blame] | 653 | |
| 654 | |
| 655 | class ByteString(Sequence): |
| 656 | |
| 657 | """This unifies bytes and bytearray. |
| 658 | |
| 659 | XXX Should add all their methods. |
| 660 | """ |
| 661 | |
Raymond Hettinger | c46759a | 2011-03-22 11:46:25 -0700 | [diff] [blame] | 662 | __slots__ = () |
| 663 | |
Guido van Rossum | d05eb00 | 2007-11-21 22:26:24 +0000 | [diff] [blame] | 664 | ByteString.register(bytes) |
| 665 | ByteString.register(bytearray) |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 666 | |
| 667 | |
| 668 | class MutableSequence(Sequence): |
| 669 | |
Raymond Hettinger | c46759a | 2011-03-22 11:46:25 -0700 | [diff] [blame] | 670 | __slots__ = () |
| 671 | |
Guido van Rossum | 840c310 | 2013-07-25 11:55:41 -0700 | [diff] [blame] | 672 | """All the operations on a read-write sequence. |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 673 | |
| 674 | Concrete subclasses must provide __new__ or __init__, |
| 675 | __getitem__, __setitem__, __delitem__, __len__, and insert(). |
| 676 | |
| 677 | """ |
| 678 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 679 | @abstractmethod |
| 680 | def __setitem__(self, index, value): |
| 681 | raise IndexError |
| 682 | |
| 683 | @abstractmethod |
| 684 | def __delitem__(self, index): |
| 685 | raise IndexError |
| 686 | |
| 687 | @abstractmethod |
| 688 | def insert(self, index, value): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 689 | 'S.insert(index, value) -- insert value before index' |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 690 | raise IndexError |
| 691 | |
| 692 | def append(self, value): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 693 | 'S.append(value) -- append value to the end of the sequence' |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 694 | self.insert(len(self), value) |
| 695 | |
Eli Bendersky | 9479d1a | 2011-03-04 05:34:58 +0000 | [diff] [blame] | 696 | def clear(self): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 697 | 'S.clear() -> None -- remove all items from S' |
Eli Bendersky | 9479d1a | 2011-03-04 05:34:58 +0000 | [diff] [blame] | 698 | try: |
| 699 | while True: |
| 700 | self.pop() |
| 701 | except IndexError: |
| 702 | pass |
| 703 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 704 | def reverse(self): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 705 | 'S.reverse() -- reverse *IN PLACE*' |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 706 | n = len(self) |
| 707 | for i in range(n//2): |
| 708 | self[i], self[n-i-1] = self[n-i-1], self[i] |
| 709 | |
| 710 | def extend(self, values): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 711 | 'S.extend(iterable) -- extend sequence by appending elements from the iterable' |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 712 | for v in values: |
| 713 | self.append(v) |
| 714 | |
| 715 | def pop(self, index=-1): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 716 | '''S.pop([index]) -> item -- remove and return item at index (default last). |
| 717 | Raise IndexError if list is empty or index is out of range. |
| 718 | ''' |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 719 | v = self[index] |
| 720 | del self[index] |
| 721 | return v |
| 722 | |
| 723 | def remove(self, value): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 724 | '''S.remove(value) -- remove first occurrence of value. |
| 725 | Raise ValueError if the value is not present. |
| 726 | ''' |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 727 | del self[self.index(value)] |
| 728 | |
| 729 | def __iadd__(self, values): |
| 730 | self.extend(values) |
Raymond Hettinger | c384b22 | 2009-05-18 15:35:26 +0000 | [diff] [blame] | 731 | return self |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 732 | |
| 733 | MutableSequence.register(list) |
Guido van Rossum | d05eb00 | 2007-11-21 22:26:24 +0000 | [diff] [blame] | 734 | MutableSequence.register(bytearray) # Multiply inheriting, see ByteString |