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 | |
Yury Selivanov | e0104ae | 2015-05-14 12:19:16 -0400 | [diff] [blame] | 12 | __all__ = ["Awaitable", "Coroutine", "AsyncIterable", "AsyncIterator", |
Yury Selivanov | 7544508 | 2015-05-11 22:57:16 -0400 | [diff] [blame] | 13 | "Hashable", "Iterable", "Iterator", "Generator", |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 14 | "Sized", "Container", "Callable", |
| 15 | "Set", "MutableSet", |
| 16 | "Mapping", "MutableMapping", |
| 17 | "MappingView", "KeysView", "ItemsView", "ValuesView", |
| 18 | "Sequence", "MutableSequence", |
Guido van Rossum | d05eb00 | 2007-11-21 22:26:24 +0000 | [diff] [blame] | 19 | "ByteString", |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 20 | ] |
| 21 | |
Christian Heimes | bf235bd | 2013-10-13 02:21:33 +0200 | [diff] [blame] | 22 | # This module has been renamed from collections.abc to _collections_abc to |
| 23 | # speed up interpreter startup. Some of the types such as MutableMapping are |
| 24 | # required early but collections module imports a lot of other modules. |
| 25 | # See issue #19218 |
| 26 | __name__ = "collections.abc" |
| 27 | |
Raymond Hettinger | 0218428 | 2012-04-05 13:31:12 -0700 | [diff] [blame] | 28 | # Private list of types that we want to register with the various ABCs |
| 29 | # so that they will pass tests like: |
| 30 | # it = iter(somebytearray) |
| 31 | # assert isinstance(it, Iterable) |
| 32 | # Note: in other implementations, these types many not be distinct |
| 33 | # and they make have their own implementation specific types that |
| 34 | # are not included on this list. |
Christian Heimes | f83be4e | 2007-11-28 09:44:38 +0000 | [diff] [blame] | 35 | bytes_iterator = type(iter(b'')) |
| 36 | bytearray_iterator = type(iter(bytearray())) |
| 37 | #callable_iterator = ??? |
| 38 | dict_keyiterator = type(iter({}.keys())) |
| 39 | dict_valueiterator = type(iter({}.values())) |
| 40 | dict_itemiterator = type(iter({}.items())) |
| 41 | list_iterator = type(iter([])) |
| 42 | list_reverseiterator = type(iter(reversed([]))) |
| 43 | range_iterator = type(iter(range(0))) |
| 44 | set_iterator = type(iter(set())) |
| 45 | str_iterator = type(iter("")) |
| 46 | tuple_iterator = type(iter(())) |
| 47 | zip_iterator = type(iter(zip())) |
| 48 | ## views ## |
| 49 | dict_keys = type({}.keys()) |
| 50 | dict_values = type({}.values()) |
| 51 | dict_items = type({}.items()) |
Christian Heimes | 0db3853 | 2007-11-29 16:21:13 +0000 | [diff] [blame] | 52 | ## misc ## |
Victor Stinner | 7b17a4e | 2012-04-20 01:41:36 +0200 | [diff] [blame] | 53 | mappingproxy = type(type.__dict__) |
Raymond Hettinger | bd60e8d | 2015-05-09 01:07:23 -0400 | [diff] [blame] | 54 | generator = type((lambda: (yield))()) |
Christian Heimes | f83be4e | 2007-11-28 09:44:38 +0000 | [diff] [blame] | 55 | |
| 56 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 57 | ### ONE-TRICK PONIES ### |
| 58 | |
| 59 | class Hashable(metaclass=ABCMeta): |
| 60 | |
Raymond Hettinger | c46759a | 2011-03-22 11:46:25 -0700 | [diff] [blame] | 61 | __slots__ = () |
| 62 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 63 | @abstractmethod |
| 64 | def __hash__(self): |
| 65 | return 0 |
| 66 | |
| 67 | @classmethod |
| 68 | def __subclasshook__(cls, C): |
| 69 | if cls is Hashable: |
| 70 | for B in C.__mro__: |
| 71 | if "__hash__" in B.__dict__: |
| 72 | if B.__dict__["__hash__"]: |
| 73 | return True |
| 74 | break |
| 75 | return NotImplemented |
| 76 | |
| 77 | |
Yury Selivanov | 56fc614 | 2015-05-29 09:01:29 -0400 | [diff] [blame^] | 78 | class _AwaitableMeta(ABCMeta): |
Yury Selivanov | 7544508 | 2015-05-11 22:57:16 -0400 | [diff] [blame] | 79 | |
| 80 | def __instancecheck__(cls, instance): |
| 81 | # 0x80 = CO_COROUTINE |
| 82 | # 0x100 = CO_ITERABLE_COROUTINE |
| 83 | # We don't want to import 'inspect' module, as |
| 84 | # a dependency for 'collections.abc'. |
| 85 | CO_COROUTINES = 0x80 | 0x100 |
| 86 | |
| 87 | if (isinstance(instance, generator) and |
| 88 | instance.gi_code.co_flags & CO_COROUTINES): |
| 89 | |
| 90 | return True |
| 91 | |
| 92 | return super().__instancecheck__(instance) |
| 93 | |
| 94 | |
Yury Selivanov | 56fc614 | 2015-05-29 09:01:29 -0400 | [diff] [blame^] | 95 | class Awaitable(metaclass=_AwaitableMeta): |
| 96 | |
| 97 | __slots__ = () |
| 98 | |
| 99 | @abstractmethod |
| 100 | def __await__(self): |
| 101 | yield |
| 102 | |
| 103 | @classmethod |
| 104 | def __subclasshook__(cls, C): |
| 105 | if cls is Awaitable: |
| 106 | for B in C.__mro__: |
| 107 | if "__await__" in B.__dict__: |
| 108 | if B.__dict__["__await__"]: |
| 109 | return True |
| 110 | break |
| 111 | return NotImplemented |
| 112 | |
| 113 | |
| 114 | class Coroutine(Awaitable): |
Yury Selivanov | 7544508 | 2015-05-11 22:57:16 -0400 | [diff] [blame] | 115 | |
| 116 | __slots__ = () |
| 117 | |
| 118 | @abstractmethod |
| 119 | def send(self, value): |
| 120 | """Send a value into the coroutine. |
| 121 | Return next yielded value or raise StopIteration. |
| 122 | """ |
| 123 | raise StopIteration |
| 124 | |
| 125 | @abstractmethod |
| 126 | def throw(self, typ, val=None, tb=None): |
| 127 | """Raise an exception in the coroutine. |
| 128 | Return next yielded value or raise StopIteration. |
| 129 | """ |
| 130 | if val is None: |
| 131 | if tb is None: |
| 132 | raise typ |
| 133 | val = typ() |
| 134 | if tb is not None: |
| 135 | val = val.with_traceback(tb) |
| 136 | raise val |
| 137 | |
| 138 | def close(self): |
| 139 | """Raise GeneratorExit inside coroutine. |
| 140 | """ |
| 141 | try: |
| 142 | self.throw(GeneratorExit) |
| 143 | except (GeneratorExit, StopIteration): |
| 144 | pass |
| 145 | else: |
| 146 | raise RuntimeError("coroutine ignored GeneratorExit") |
| 147 | |
Yury Selivanov | 7544508 | 2015-05-11 22:57:16 -0400 | [diff] [blame] | 148 | @classmethod |
| 149 | def __subclasshook__(cls, C): |
Yury Selivanov | 56fc614 | 2015-05-29 09:01:29 -0400 | [diff] [blame^] | 150 | if cls is Coroutine: |
| 151 | mro = C.__mro__ |
| 152 | for method in ('__await__', 'send', 'throw', 'close'): |
| 153 | for base in mro: |
| 154 | if method in base.__dict__: |
| 155 | break |
| 156 | else: |
| 157 | return NotImplemented |
| 158 | return True |
Yury Selivanov | 7544508 | 2015-05-11 22:57:16 -0400 | [diff] [blame] | 159 | return NotImplemented |
| 160 | |
Yury Selivanov | 7544508 | 2015-05-11 22:57:16 -0400 | [diff] [blame] | 161 | |
Yury Selivanov | e0104ae | 2015-05-14 12:19:16 -0400 | [diff] [blame] | 162 | class AsyncIterable(metaclass=ABCMeta): |
| 163 | |
| 164 | __slots__ = () |
| 165 | |
| 166 | @abstractmethod |
| 167 | async def __aiter__(self): |
| 168 | return AsyncIterator() |
| 169 | |
| 170 | @classmethod |
| 171 | def __subclasshook__(cls, C): |
| 172 | if cls is AsyncIterable: |
| 173 | if any("__aiter__" in B.__dict__ for B in C.__mro__): |
| 174 | return True |
| 175 | return NotImplemented |
| 176 | |
| 177 | |
| 178 | class AsyncIterator(AsyncIterable): |
| 179 | |
| 180 | __slots__ = () |
| 181 | |
| 182 | @abstractmethod |
| 183 | async def __anext__(self): |
| 184 | """Return the next item or raise StopAsyncIteration when exhausted.""" |
| 185 | raise StopAsyncIteration |
| 186 | |
| 187 | async def __aiter__(self): |
| 188 | return self |
| 189 | |
| 190 | @classmethod |
| 191 | def __subclasshook__(cls, C): |
| 192 | if cls is AsyncIterator: |
| 193 | if (any("__anext__" in B.__dict__ for B in C.__mro__) and |
| 194 | any("__aiter__" in B.__dict__ for B in C.__mro__)): |
| 195 | return True |
| 196 | return NotImplemented |
| 197 | |
| 198 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 199 | class Iterable(metaclass=ABCMeta): |
| 200 | |
Raymond Hettinger | c46759a | 2011-03-22 11:46:25 -0700 | [diff] [blame] | 201 | __slots__ = () |
| 202 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 203 | @abstractmethod |
| 204 | def __iter__(self): |
| 205 | while False: |
| 206 | yield None |
| 207 | |
| 208 | @classmethod |
| 209 | def __subclasshook__(cls, C): |
| 210 | if cls is Iterable: |
| 211 | if any("__iter__" in B.__dict__ for B in C.__mro__): |
| 212 | return True |
| 213 | return NotImplemented |
| 214 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 215 | |
Raymond Hettinger | 74b6495 | 2008-02-09 02:53:48 +0000 | [diff] [blame] | 216 | class Iterator(Iterable): |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 217 | |
Raymond Hettinger | c46759a | 2011-03-22 11:46:25 -0700 | [diff] [blame] | 218 | __slots__ = () |
| 219 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 220 | @abstractmethod |
| 221 | def __next__(self): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 222 | 'Return the next item from the iterator. When exhausted, raise StopIteration' |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 223 | raise StopIteration |
| 224 | |
| 225 | def __iter__(self): |
| 226 | return self |
| 227 | |
| 228 | @classmethod |
| 229 | def __subclasshook__(cls, C): |
| 230 | if cls is Iterator: |
Raymond Hettinger | ead2222 | 2010-11-29 03:56:12 +0000 | [diff] [blame] | 231 | if (any("__next__" in B.__dict__ for B in C.__mro__) and |
| 232 | any("__iter__" in B.__dict__ for B in C.__mro__)): |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 233 | return True |
| 234 | return NotImplemented |
| 235 | |
Christian Heimes | f83be4e | 2007-11-28 09:44:38 +0000 | [diff] [blame] | 236 | Iterator.register(bytes_iterator) |
| 237 | Iterator.register(bytearray_iterator) |
| 238 | #Iterator.register(callable_iterator) |
| 239 | Iterator.register(dict_keyiterator) |
| 240 | Iterator.register(dict_valueiterator) |
| 241 | Iterator.register(dict_itemiterator) |
| 242 | Iterator.register(list_iterator) |
| 243 | Iterator.register(list_reverseiterator) |
| 244 | Iterator.register(range_iterator) |
| 245 | Iterator.register(set_iterator) |
| 246 | Iterator.register(str_iterator) |
| 247 | Iterator.register(tuple_iterator) |
| 248 | Iterator.register(zip_iterator) |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 249 | |
Raymond Hettinger | bd60e8d | 2015-05-09 01:07:23 -0400 | [diff] [blame] | 250 | |
| 251 | class Generator(Iterator): |
| 252 | |
| 253 | __slots__ = () |
| 254 | |
| 255 | def __next__(self): |
| 256 | """Return the next item from the generator. |
| 257 | When exhausted, raise StopIteration. |
| 258 | """ |
| 259 | return self.send(None) |
| 260 | |
| 261 | @abstractmethod |
| 262 | def send(self, value): |
| 263 | """Send a value into the generator. |
| 264 | Return next yielded value or raise StopIteration. |
| 265 | """ |
| 266 | raise StopIteration |
| 267 | |
| 268 | @abstractmethod |
| 269 | def throw(self, typ, val=None, tb=None): |
| 270 | """Raise an exception in the generator. |
| 271 | Return next yielded value or raise StopIteration. |
| 272 | """ |
| 273 | if val is None: |
| 274 | if tb is None: |
| 275 | raise typ |
| 276 | val = typ() |
| 277 | if tb is not None: |
| 278 | val = val.with_traceback(tb) |
| 279 | raise val |
| 280 | |
| 281 | def close(self): |
| 282 | """Raise GeneratorExit inside generator. |
| 283 | """ |
| 284 | try: |
| 285 | self.throw(GeneratorExit) |
| 286 | except (GeneratorExit, StopIteration): |
| 287 | pass |
| 288 | else: |
| 289 | raise RuntimeError("generator ignored GeneratorExit") |
| 290 | |
| 291 | @classmethod |
| 292 | def __subclasshook__(cls, C): |
| 293 | if cls is Generator: |
| 294 | mro = C.__mro__ |
| 295 | for method in ('__iter__', '__next__', 'send', 'throw', 'close'): |
| 296 | for base in mro: |
| 297 | if method in base.__dict__: |
| 298 | break |
| 299 | else: |
| 300 | return NotImplemented |
| 301 | return True |
| 302 | return NotImplemented |
| 303 | |
| 304 | |
| 305 | Generator.register(generator) |
| 306 | |
| 307 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 308 | class Sized(metaclass=ABCMeta): |
| 309 | |
Raymond Hettinger | c46759a | 2011-03-22 11:46:25 -0700 | [diff] [blame] | 310 | __slots__ = () |
| 311 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 312 | @abstractmethod |
| 313 | def __len__(self): |
| 314 | return 0 |
| 315 | |
| 316 | @classmethod |
| 317 | def __subclasshook__(cls, C): |
| 318 | if cls is Sized: |
| 319 | if any("__len__" in B.__dict__ for B in C.__mro__): |
| 320 | return True |
| 321 | return NotImplemented |
| 322 | |
| 323 | |
| 324 | class Container(metaclass=ABCMeta): |
| 325 | |
Raymond Hettinger | c46759a | 2011-03-22 11:46:25 -0700 | [diff] [blame] | 326 | __slots__ = () |
| 327 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 328 | @abstractmethod |
| 329 | def __contains__(self, x): |
| 330 | return False |
| 331 | |
| 332 | @classmethod |
| 333 | def __subclasshook__(cls, C): |
| 334 | if cls is Container: |
| 335 | if any("__contains__" in B.__dict__ for B in C.__mro__): |
| 336 | return True |
| 337 | return NotImplemented |
| 338 | |
| 339 | |
| 340 | class Callable(metaclass=ABCMeta): |
| 341 | |
Raymond Hettinger | c46759a | 2011-03-22 11:46:25 -0700 | [diff] [blame] | 342 | __slots__ = () |
| 343 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 344 | @abstractmethod |
Christian Heimes | 7864476 | 2008-03-04 23:39:23 +0000 | [diff] [blame] | 345 | def __call__(self, *args, **kwds): |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 346 | return False |
| 347 | |
| 348 | @classmethod |
| 349 | def __subclasshook__(cls, C): |
| 350 | if cls is Callable: |
| 351 | if any("__call__" in B.__dict__ for B in C.__mro__): |
| 352 | return True |
| 353 | return NotImplemented |
| 354 | |
| 355 | |
| 356 | ### SETS ### |
| 357 | |
| 358 | |
Raymond Hettinger | 74b6495 | 2008-02-09 02:53:48 +0000 | [diff] [blame] | 359 | class Set(Sized, Iterable, Container): |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 360 | |
| 361 | """A set is a finite, iterable container. |
| 362 | |
| 363 | This class provides concrete generic implementations of all |
| 364 | methods except for __contains__, __iter__ and __len__. |
| 365 | |
| 366 | To override the comparisons (presumably for speed, as the |
Raymond Hettinger | 11cda47 | 2014-07-03 00:31:30 +0100 | [diff] [blame] | 367 | semantics are fixed), redefine __le__ and __ge__, |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 368 | then the other operations will automatically follow suit. |
| 369 | """ |
| 370 | |
Raymond Hettinger | c46759a | 2011-03-22 11:46:25 -0700 | [diff] [blame] | 371 | __slots__ = () |
| 372 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 373 | def __le__(self, other): |
| 374 | if not isinstance(other, Set): |
| 375 | return NotImplemented |
| 376 | if len(self) > len(other): |
| 377 | return False |
| 378 | for elem in self: |
| 379 | if elem not in other: |
| 380 | return False |
| 381 | return True |
| 382 | |
| 383 | def __lt__(self, other): |
| 384 | if not isinstance(other, Set): |
| 385 | return NotImplemented |
| 386 | return len(self) < len(other) and self.__le__(other) |
| 387 | |
Raymond Hettinger | 7190942 | 2008-02-09 00:08:16 +0000 | [diff] [blame] | 388 | def __gt__(self, other): |
| 389 | if not isinstance(other, Set): |
| 390 | return NotImplemented |
Raymond Hettinger | dd5e53a | 2014-05-26 00:09:04 -0700 | [diff] [blame] | 391 | return len(self) > len(other) and self.__ge__(other) |
Raymond Hettinger | 7190942 | 2008-02-09 00:08:16 +0000 | [diff] [blame] | 392 | |
| 393 | def __ge__(self, other): |
| 394 | if not isinstance(other, Set): |
| 395 | return NotImplemented |
Raymond Hettinger | dd5e53a | 2014-05-26 00:09:04 -0700 | [diff] [blame] | 396 | if len(self) < len(other): |
| 397 | return False |
| 398 | for elem in other: |
| 399 | if elem not in self: |
| 400 | return False |
| 401 | return True |
Raymond Hettinger | 7190942 | 2008-02-09 00:08:16 +0000 | [diff] [blame] | 402 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 403 | def __eq__(self, other): |
| 404 | if not isinstance(other, Set): |
| 405 | return NotImplemented |
| 406 | return len(self) == len(other) and self.__le__(other) |
| 407 | |
| 408 | @classmethod |
| 409 | def _from_iterable(cls, it): |
Raymond Hettinger | 8284c4a | 2008-02-06 20:47:09 +0000 | [diff] [blame] | 410 | '''Construct an instance of the class from any iterable input. |
| 411 | |
| 412 | Must override this method if the class constructor signature |
Raymond Hettinger | 7aebb64 | 2008-02-09 03:25:08 +0000 | [diff] [blame] | 413 | does not accept an iterable for an input. |
Raymond Hettinger | 8284c4a | 2008-02-06 20:47:09 +0000 | [diff] [blame] | 414 | ''' |
Raymond Hettinger | 7aebb64 | 2008-02-09 03:25:08 +0000 | [diff] [blame] | 415 | return cls(it) |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 416 | |
| 417 | def __and__(self, other): |
| 418 | if not isinstance(other, Iterable): |
| 419 | return NotImplemented |
| 420 | return self._from_iterable(value for value in other if value in self) |
| 421 | |
Raymond Hettinger | dd5e53a | 2014-05-26 00:09:04 -0700 | [diff] [blame] | 422 | __rand__ = __and__ |
| 423 | |
Christian Heimes | 190d79e | 2008-01-30 11:58:22 +0000 | [diff] [blame] | 424 | def isdisjoint(self, other): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 425 | 'Return True if two sets have a null intersection.' |
Christian Heimes | 190d79e | 2008-01-30 11:58:22 +0000 | [diff] [blame] | 426 | for value in other: |
| 427 | if value in self: |
| 428 | return False |
| 429 | return True |
| 430 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 431 | def __or__(self, other): |
| 432 | if not isinstance(other, Iterable): |
| 433 | return NotImplemented |
Christian Heimes | 7864476 | 2008-03-04 23:39:23 +0000 | [diff] [blame] | 434 | chain = (e for s in (self, other) for e in s) |
| 435 | return self._from_iterable(chain) |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 436 | |
Raymond Hettinger | dd5e53a | 2014-05-26 00:09:04 -0700 | [diff] [blame] | 437 | __ror__ = __or__ |
| 438 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 439 | def __sub__(self, other): |
| 440 | if not isinstance(other, Set): |
| 441 | if not isinstance(other, Iterable): |
| 442 | return NotImplemented |
| 443 | other = self._from_iterable(other) |
| 444 | return self._from_iterable(value for value in self |
| 445 | if value not in other) |
| 446 | |
Raymond Hettinger | dd5e53a | 2014-05-26 00:09:04 -0700 | [diff] [blame] | 447 | def __rsub__(self, other): |
| 448 | if not isinstance(other, Set): |
| 449 | if not isinstance(other, Iterable): |
| 450 | return NotImplemented |
| 451 | other = self._from_iterable(other) |
| 452 | return self._from_iterable(value for value in other |
| 453 | if value not in self) |
| 454 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 455 | def __xor__(self, other): |
| 456 | if not isinstance(other, Set): |
| 457 | if not isinstance(other, Iterable): |
| 458 | return NotImplemented |
| 459 | other = self._from_iterable(other) |
| 460 | return (self - other) | (other - self) |
| 461 | |
Raymond Hettinger | dd5e53a | 2014-05-26 00:09:04 -0700 | [diff] [blame] | 462 | __rxor__ = __xor__ |
| 463 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 464 | def _hash(self): |
| 465 | """Compute the hash value of a set. |
| 466 | |
| 467 | Note that we don't define __hash__: not all sets are hashable. |
| 468 | But if you define a hashable set type, its __hash__ should |
| 469 | call this function. |
| 470 | |
| 471 | This must be compatible __eq__. |
| 472 | |
| 473 | All sets ought to compare equal if they contain the same |
| 474 | elements, regardless of how they are implemented, and |
| 475 | regardless of the order of the elements; so there's not much |
| 476 | freedom for __eq__ or __hash__. We match the algorithm used |
| 477 | by the built-in frozenset type. |
| 478 | """ |
Christian Heimes | a37d4c6 | 2007-12-04 23:02:19 +0000 | [diff] [blame] | 479 | MAX = sys.maxsize |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 480 | MASK = 2 * MAX + 1 |
| 481 | n = len(self) |
| 482 | h = 1927868237 * (n + 1) |
| 483 | h &= MASK |
| 484 | for x in self: |
| 485 | hx = hash(x) |
| 486 | h ^= (hx ^ (hx << 16) ^ 89869747) * 3644798167 |
| 487 | h &= MASK |
| 488 | h = h * 69069 + 907133923 |
| 489 | h &= MASK |
| 490 | if h > MAX: |
| 491 | h -= MASK + 1 |
| 492 | if h == -1: |
| 493 | h = 590923713 |
| 494 | return h |
| 495 | |
| 496 | Set.register(frozenset) |
| 497 | |
| 498 | |
| 499 | class MutableSet(Set): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 500 | """A mutable set is a finite, iterable container. |
| 501 | |
| 502 | This class provides concrete generic implementations of all |
| 503 | methods except for __contains__, __iter__, __len__, |
| 504 | add(), and discard(). |
| 505 | |
| 506 | To override the comparisons (presumably for speed, as the |
| 507 | semantics are fixed), all you have to do is redefine __le__ and |
| 508 | then the other operations will automatically follow suit. |
| 509 | """ |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 510 | |
Raymond Hettinger | c46759a | 2011-03-22 11:46:25 -0700 | [diff] [blame] | 511 | __slots__ = () |
| 512 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 513 | @abstractmethod |
| 514 | def add(self, value): |
Benjamin Peterson | 058e31e | 2009-01-16 03:54:08 +0000 | [diff] [blame] | 515 | """Add an element.""" |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 516 | raise NotImplementedError |
| 517 | |
| 518 | @abstractmethod |
| 519 | def discard(self, value): |
Benjamin Peterson | 058e31e | 2009-01-16 03:54:08 +0000 | [diff] [blame] | 520 | """Remove an element. Do not raise an exception if absent.""" |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 521 | raise NotImplementedError |
| 522 | |
Christian Heimes | 190d79e | 2008-01-30 11:58:22 +0000 | [diff] [blame] | 523 | def remove(self, value): |
| 524 | """Remove an element. If not a member, raise a KeyError.""" |
| 525 | if value not in self: |
| 526 | raise KeyError(value) |
| 527 | self.discard(value) |
| 528 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 529 | def pop(self): |
| 530 | """Return the popped value. Raise KeyError if empty.""" |
| 531 | it = iter(self) |
| 532 | try: |
Raymond Hettinger | ae65018 | 2009-01-28 23:33:59 +0000 | [diff] [blame] | 533 | value = next(it) |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 534 | except StopIteration: |
| 535 | raise KeyError |
| 536 | self.discard(value) |
| 537 | return value |
| 538 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 539 | def clear(self): |
| 540 | """This is slow (creates N new iterators!) but effective.""" |
| 541 | try: |
| 542 | while True: |
| 543 | self.pop() |
| 544 | except KeyError: |
| 545 | pass |
| 546 | |
Raymond Hettinger | b3d89a4 | 2011-01-12 20:37:47 +0000 | [diff] [blame] | 547 | def __ior__(self, it): |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 548 | for value in it: |
| 549 | self.add(value) |
| 550 | return self |
| 551 | |
Raymond Hettinger | b3d89a4 | 2011-01-12 20:37:47 +0000 | [diff] [blame] | 552 | def __iand__(self, it): |
Raymond Hettinger | 3f10a95 | 2009-04-01 19:05:50 +0000 | [diff] [blame] | 553 | for value in (self - it): |
| 554 | self.discard(value) |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 555 | return self |
| 556 | |
Raymond Hettinger | b3d89a4 | 2011-01-12 20:37:47 +0000 | [diff] [blame] | 557 | def __ixor__(self, it): |
Daniel Stutzbach | 31da5b2 | 2010-08-24 20:49:57 +0000 | [diff] [blame] | 558 | if it is self: |
| 559 | self.clear() |
| 560 | else: |
| 561 | if not isinstance(it, Set): |
| 562 | it = self._from_iterable(it) |
| 563 | for value in it: |
| 564 | if value in self: |
| 565 | self.discard(value) |
| 566 | else: |
| 567 | self.add(value) |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 568 | return self |
| 569 | |
Raymond Hettinger | b3d89a4 | 2011-01-12 20:37:47 +0000 | [diff] [blame] | 570 | def __isub__(self, it): |
Daniel Stutzbach | 31da5b2 | 2010-08-24 20:49:57 +0000 | [diff] [blame] | 571 | if it is self: |
| 572 | self.clear() |
| 573 | else: |
| 574 | for value in it: |
| 575 | self.discard(value) |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 576 | return self |
| 577 | |
| 578 | MutableSet.register(set) |
| 579 | |
| 580 | |
| 581 | ### MAPPINGS ### |
| 582 | |
| 583 | |
Raymond Hettinger | 74b6495 | 2008-02-09 02:53:48 +0000 | [diff] [blame] | 584 | class Mapping(Sized, Iterable, Container): |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 585 | |
Raymond Hettinger | c46759a | 2011-03-22 11:46:25 -0700 | [diff] [blame] | 586 | __slots__ = () |
| 587 | |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 588 | """A Mapping is a generic container for associating key/value |
| 589 | pairs. |
| 590 | |
| 591 | This class provides concrete generic implementations of all |
| 592 | methods except for __getitem__, __iter__, and __len__. |
| 593 | |
| 594 | """ |
| 595 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 596 | @abstractmethod |
| 597 | def __getitem__(self, key): |
| 598 | raise KeyError |
| 599 | |
| 600 | def get(self, key, default=None): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 601 | '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] | 602 | try: |
| 603 | return self[key] |
| 604 | except KeyError: |
| 605 | return default |
| 606 | |
| 607 | def __contains__(self, key): |
| 608 | try: |
| 609 | self[key] |
| 610 | except KeyError: |
| 611 | return False |
| 612 | else: |
| 613 | return True |
| 614 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 615 | def keys(self): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 616 | "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] | 617 | return KeysView(self) |
| 618 | |
| 619 | def items(self): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 620 | "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] | 621 | return ItemsView(self) |
| 622 | |
| 623 | def values(self): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 624 | "D.values() -> an object providing a view on D's values" |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 625 | return ValuesView(self) |
| 626 | |
Raymond Hettinger | b9da9bc | 2008-02-04 20:44:31 +0000 | [diff] [blame] | 627 | def __eq__(self, other): |
Benjamin Peterson | 4ad6bd5 | 2010-05-21 20:55:22 +0000 | [diff] [blame] | 628 | if not isinstance(other, Mapping): |
| 629 | return NotImplemented |
| 630 | return dict(self.items()) == dict(other.items()) |
Raymond Hettinger | b9da9bc | 2008-02-04 20:44:31 +0000 | [diff] [blame] | 631 | |
Victor Stinner | 7b17a4e | 2012-04-20 01:41:36 +0200 | [diff] [blame] | 632 | Mapping.register(mappingproxy) |
| 633 | |
Christian Heimes | 2202f87 | 2008-02-06 14:31:34 +0000 | [diff] [blame] | 634 | |
Raymond Hettinger | bfd0612 | 2008-02-09 10:04:32 +0000 | [diff] [blame] | 635 | class MappingView(Sized): |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 636 | |
Raymond Hettinger | 3170d1c | 2014-05-03 19:06:32 -0700 | [diff] [blame] | 637 | __slots__ = '_mapping', |
| 638 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 639 | def __init__(self, mapping): |
| 640 | self._mapping = mapping |
| 641 | |
| 642 | def __len__(self): |
| 643 | return len(self._mapping) |
| 644 | |
Raymond Hettinger | 89fc2b7 | 2009-02-27 07:47:32 +0000 | [diff] [blame] | 645 | def __repr__(self): |
| 646 | return '{0.__class__.__name__}({0._mapping!r})'.format(self) |
| 647 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 648 | |
| 649 | class KeysView(MappingView, Set): |
| 650 | |
Raymond Hettinger | 3170d1c | 2014-05-03 19:06:32 -0700 | [diff] [blame] | 651 | __slots__ = () |
| 652 | |
Raymond Hettinger | 9117c75 | 2010-08-22 07:44:24 +0000 | [diff] [blame] | 653 | @classmethod |
| 654 | def _from_iterable(self, it): |
| 655 | return set(it) |
| 656 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 657 | def __contains__(self, key): |
| 658 | return key in self._mapping |
| 659 | |
| 660 | def __iter__(self): |
Philip Jenvey | 4993cc0 | 2012-10-01 12:53:43 -0700 | [diff] [blame] | 661 | yield from self._mapping |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 662 | |
Christian Heimes | f83be4e | 2007-11-28 09:44:38 +0000 | [diff] [blame] | 663 | KeysView.register(dict_keys) |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 664 | |
| 665 | |
| 666 | class ItemsView(MappingView, Set): |
| 667 | |
Raymond Hettinger | 3170d1c | 2014-05-03 19:06:32 -0700 | [diff] [blame] | 668 | __slots__ = () |
| 669 | |
Raymond Hettinger | 9117c75 | 2010-08-22 07:44:24 +0000 | [diff] [blame] | 670 | @classmethod |
| 671 | def _from_iterable(self, it): |
| 672 | return set(it) |
| 673 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 674 | def __contains__(self, item): |
| 675 | key, value = item |
| 676 | try: |
| 677 | v = self._mapping[key] |
| 678 | except KeyError: |
| 679 | return False |
| 680 | else: |
| 681 | return v == value |
| 682 | |
| 683 | def __iter__(self): |
| 684 | for key in self._mapping: |
| 685 | yield (key, self._mapping[key]) |
| 686 | |
Christian Heimes | f83be4e | 2007-11-28 09:44:38 +0000 | [diff] [blame] | 687 | ItemsView.register(dict_items) |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 688 | |
| 689 | |
| 690 | class ValuesView(MappingView): |
| 691 | |
Raymond Hettinger | 3170d1c | 2014-05-03 19:06:32 -0700 | [diff] [blame] | 692 | __slots__ = () |
| 693 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 694 | def __contains__(self, value): |
| 695 | for key in self._mapping: |
| 696 | if value == self._mapping[key]: |
| 697 | return True |
| 698 | return False |
| 699 | |
| 700 | def __iter__(self): |
| 701 | for key in self._mapping: |
| 702 | yield self._mapping[key] |
| 703 | |
Christian Heimes | f83be4e | 2007-11-28 09:44:38 +0000 | [diff] [blame] | 704 | ValuesView.register(dict_values) |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 705 | |
| 706 | |
| 707 | class MutableMapping(Mapping): |
| 708 | |
Raymond Hettinger | c46759a | 2011-03-22 11:46:25 -0700 | [diff] [blame] | 709 | __slots__ = () |
| 710 | |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 711 | """A MutableMapping is a generic container for associating |
| 712 | key/value pairs. |
| 713 | |
| 714 | This class provides concrete generic implementations of all |
| 715 | methods except for __getitem__, __setitem__, __delitem__, |
| 716 | __iter__, and __len__. |
| 717 | |
| 718 | """ |
| 719 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 720 | @abstractmethod |
| 721 | def __setitem__(self, key, value): |
| 722 | raise KeyError |
| 723 | |
| 724 | @abstractmethod |
| 725 | def __delitem__(self, key): |
| 726 | raise KeyError |
| 727 | |
| 728 | __marker = object() |
| 729 | |
| 730 | def pop(self, key, default=__marker): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 731 | '''D.pop(k[,d]) -> v, remove specified key and return the corresponding value. |
| 732 | If key is not found, d is returned if given, otherwise KeyError is raised. |
| 733 | ''' |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 734 | try: |
| 735 | value = self[key] |
| 736 | except KeyError: |
| 737 | if default is self.__marker: |
| 738 | raise |
| 739 | return default |
| 740 | else: |
| 741 | del self[key] |
| 742 | return value |
| 743 | |
| 744 | def popitem(self): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 745 | '''D.popitem() -> (k, v), remove and return some (key, value) pair |
| 746 | as a 2-tuple; but raise KeyError if D is empty. |
| 747 | ''' |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 748 | try: |
| 749 | key = next(iter(self)) |
| 750 | except StopIteration: |
| 751 | raise KeyError |
| 752 | value = self[key] |
| 753 | del self[key] |
| 754 | return key, value |
| 755 | |
| 756 | def clear(self): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 757 | 'D.clear() -> None. Remove all items from D.' |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 758 | try: |
| 759 | while True: |
| 760 | self.popitem() |
| 761 | except KeyError: |
| 762 | pass |
| 763 | |
Mark Dickinson | b214e90 | 2010-07-11 18:53:06 +0000 | [diff] [blame] | 764 | def update(*args, **kwds): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 765 | ''' D.update([E, ]**F) -> None. Update D from mapping/iterable E and F. |
| 766 | If E present and has a .keys() method, does: for k in E: D[k] = E[k] |
| 767 | If E present and lacks .keys() method, does: for (k, v) in E: D[k] = v |
| 768 | In either case, this is followed by: for k, v in F.items(): D[k] = v |
| 769 | ''' |
Serhiy Storchaka | ae5cb21 | 2014-11-27 16:25:51 +0200 | [diff] [blame] | 770 | if not args: |
| 771 | raise TypeError("descriptor 'update' of 'MutableMapping' object " |
| 772 | "needs an argument") |
| 773 | self, *args = args |
| 774 | if len(args) > 1: |
| 775 | raise TypeError('update expected at most 1 arguments, got %d' % |
| 776 | len(args)) |
| 777 | if args: |
| 778 | other = args[0] |
| 779 | if isinstance(other, Mapping): |
| 780 | for key in other: |
| 781 | self[key] = other[key] |
| 782 | elif hasattr(other, "keys"): |
| 783 | for key in other.keys(): |
| 784 | self[key] = other[key] |
| 785 | else: |
| 786 | for key, value in other: |
| 787 | self[key] = value |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 788 | for key, value in kwds.items(): |
| 789 | self[key] = value |
| 790 | |
Raymond Hettinger | b9da9bc | 2008-02-04 20:44:31 +0000 | [diff] [blame] | 791 | def setdefault(self, key, default=None): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 792 | '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] | 793 | try: |
| 794 | return self[key] |
| 795 | except KeyError: |
| 796 | self[key] = default |
| 797 | return default |
| 798 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 799 | MutableMapping.register(dict) |
| 800 | |
| 801 | |
| 802 | ### SEQUENCES ### |
| 803 | |
| 804 | |
Raymond Hettinger | 74b6495 | 2008-02-09 02:53:48 +0000 | [diff] [blame] | 805 | class Sequence(Sized, Iterable, Container): |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 806 | |
| 807 | """All the operations on a read-only sequence. |
| 808 | |
| 809 | Concrete subclasses must override __new__ or __init__, |
| 810 | __getitem__, and __len__. |
| 811 | """ |
| 812 | |
Raymond Hettinger | c46759a | 2011-03-22 11:46:25 -0700 | [diff] [blame] | 813 | __slots__ = () |
| 814 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 815 | @abstractmethod |
| 816 | def __getitem__(self, index): |
| 817 | raise IndexError |
| 818 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 819 | def __iter__(self): |
| 820 | i = 0 |
Raymond Hettinger | 7190942 | 2008-02-09 00:08:16 +0000 | [diff] [blame] | 821 | try: |
| 822 | while True: |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 823 | v = self[i] |
Raymond Hettinger | 7190942 | 2008-02-09 00:08:16 +0000 | [diff] [blame] | 824 | yield v |
| 825 | i += 1 |
| 826 | except IndexError: |
| 827 | return |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 828 | |
| 829 | def __contains__(self, value): |
| 830 | for v in self: |
| 831 | if v == value: |
| 832 | return True |
| 833 | return False |
| 834 | |
| 835 | def __reversed__(self): |
| 836 | for i in reversed(range(len(self))): |
| 837 | yield self[i] |
| 838 | |
Raymond Hettinger | ec219ba | 2015-05-22 19:29:22 -0700 | [diff] [blame] | 839 | def index(self, value, start=0, stop=None): |
| 840 | '''S.index(value, [start, [stop]]) -> integer -- return first index of value. |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 841 | Raises ValueError if the value is not present. |
| 842 | ''' |
Raymond Hettinger | ec219ba | 2015-05-22 19:29:22 -0700 | [diff] [blame] | 843 | if start is not None and start < 0: |
| 844 | start = max(len(self) + start, 0) |
| 845 | if stop is not None and stop < 0: |
| 846 | stop += len(self) |
| 847 | |
| 848 | i = start |
| 849 | while stop is None or i < stop: |
| 850 | try: |
| 851 | if self[i] == value: |
| 852 | return i |
| 853 | except IndexError: |
| 854 | break |
| 855 | i += 1 |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 856 | raise ValueError |
| 857 | |
| 858 | def count(self, value): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 859 | 'S.count(value) -> integer -- return number of occurrences of value' |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 860 | return sum(1 for v in self if v == value) |
| 861 | |
| 862 | Sequence.register(tuple) |
Guido van Rossum | 3172c5d | 2007-10-16 18:12:55 +0000 | [diff] [blame] | 863 | Sequence.register(str) |
Raymond Hettinger | 9aa53c2 | 2009-02-24 11:25:35 +0000 | [diff] [blame] | 864 | Sequence.register(range) |
Nick Coghlan | 45163cc | 2013-10-02 22:31:47 +1000 | [diff] [blame] | 865 | Sequence.register(memoryview) |
Guido van Rossum | d05eb00 | 2007-11-21 22:26:24 +0000 | [diff] [blame] | 866 | |
| 867 | |
| 868 | class ByteString(Sequence): |
| 869 | |
| 870 | """This unifies bytes and bytearray. |
| 871 | |
| 872 | XXX Should add all their methods. |
| 873 | """ |
| 874 | |
Raymond Hettinger | c46759a | 2011-03-22 11:46:25 -0700 | [diff] [blame] | 875 | __slots__ = () |
| 876 | |
Guido van Rossum | d05eb00 | 2007-11-21 22:26:24 +0000 | [diff] [blame] | 877 | ByteString.register(bytes) |
| 878 | ByteString.register(bytearray) |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 879 | |
| 880 | |
| 881 | class MutableSequence(Sequence): |
| 882 | |
Raymond Hettinger | c46759a | 2011-03-22 11:46:25 -0700 | [diff] [blame] | 883 | __slots__ = () |
| 884 | |
Guido van Rossum | 840c310 | 2013-07-25 11:55:41 -0700 | [diff] [blame] | 885 | """All the operations on a read-write sequence. |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 886 | |
| 887 | Concrete subclasses must provide __new__ or __init__, |
| 888 | __getitem__, __setitem__, __delitem__, __len__, and insert(). |
| 889 | |
| 890 | """ |
| 891 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 892 | @abstractmethod |
| 893 | def __setitem__(self, index, value): |
| 894 | raise IndexError |
| 895 | |
| 896 | @abstractmethod |
| 897 | def __delitem__(self, index): |
| 898 | raise IndexError |
| 899 | |
| 900 | @abstractmethod |
| 901 | def insert(self, index, value): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 902 | 'S.insert(index, value) -- insert value before index' |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 903 | raise IndexError |
| 904 | |
| 905 | def append(self, value): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 906 | 'S.append(value) -- append value to the end of the sequence' |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 907 | self.insert(len(self), value) |
| 908 | |
Eli Bendersky | 9479d1a | 2011-03-04 05:34:58 +0000 | [diff] [blame] | 909 | def clear(self): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 910 | 'S.clear() -> None -- remove all items from S' |
Eli Bendersky | 9479d1a | 2011-03-04 05:34:58 +0000 | [diff] [blame] | 911 | try: |
| 912 | while True: |
| 913 | self.pop() |
| 914 | except IndexError: |
| 915 | pass |
| 916 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 917 | def reverse(self): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 918 | 'S.reverse() -- reverse *IN PLACE*' |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 919 | n = len(self) |
| 920 | for i in range(n//2): |
| 921 | self[i], self[n-i-1] = self[n-i-1], self[i] |
| 922 | |
| 923 | def extend(self, values): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 924 | 'S.extend(iterable) -- extend sequence by appending elements from the iterable' |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 925 | for v in values: |
| 926 | self.append(v) |
| 927 | |
| 928 | def pop(self, index=-1): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 929 | '''S.pop([index]) -> item -- remove and return item at index (default last). |
| 930 | Raise IndexError if list is empty or index is out of range. |
| 931 | ''' |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 932 | v = self[index] |
| 933 | del self[index] |
| 934 | return v |
| 935 | |
| 936 | def remove(self, value): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 937 | '''S.remove(value) -- remove first occurrence of value. |
| 938 | Raise ValueError if the value is not present. |
| 939 | ''' |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 940 | del self[self.index(value)] |
| 941 | |
| 942 | def __iadd__(self, values): |
| 943 | self.extend(values) |
Raymond Hettinger | c384b22 | 2009-05-18 15:35:26 +0000 | [diff] [blame] | 944 | return self |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 945 | |
| 946 | MutableSequence.register(list) |
Guido van Rossum | d05eb00 | 2007-11-21 22:26:24 +0000 | [diff] [blame] | 947 | MutableSequence.register(bytearray) # Multiply inheriting, see ByteString |