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", |
Guido van Rossum | 16ca06b | 2016-04-04 10:59:29 -0700 | [diff] [blame] | 13 | "Hashable", "Iterable", "Iterator", "Generator", "Reversible", |
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))()) |
Yury Selivanov | 5376ba9 | 2015-06-22 12:19:30 -0400 | [diff] [blame] | 55 | ## coroutine ## |
| 56 | async def _coro(): pass |
| 57 | _coro = _coro() |
| 58 | coroutine = type(_coro) |
| 59 | _coro.close() # Prevent ResourceWarning |
| 60 | del _coro |
Christian Heimes | f83be4e | 2007-11-28 09:44:38 +0000 | [diff] [blame] | 61 | |
| 62 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 63 | ### ONE-TRICK PONIES ### |
| 64 | |
| 65 | class Hashable(metaclass=ABCMeta): |
| 66 | |
Raymond Hettinger | c46759a | 2011-03-22 11:46:25 -0700 | [diff] [blame] | 67 | __slots__ = () |
| 68 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 69 | @abstractmethod |
| 70 | def __hash__(self): |
| 71 | return 0 |
| 72 | |
| 73 | @classmethod |
| 74 | def __subclasshook__(cls, C): |
| 75 | if cls is Hashable: |
| 76 | for B in C.__mro__: |
| 77 | if "__hash__" in B.__dict__: |
| 78 | if B.__dict__["__hash__"]: |
| 79 | return True |
| 80 | break |
| 81 | return NotImplemented |
| 82 | |
| 83 | |
Yury Selivanov | fdbeb2b | 2015-07-03 13:11:35 -0400 | [diff] [blame] | 84 | class Awaitable(metaclass=ABCMeta): |
Yury Selivanov | 56fc614 | 2015-05-29 09:01:29 -0400 | [diff] [blame] | 85 | |
| 86 | __slots__ = () |
| 87 | |
| 88 | @abstractmethod |
| 89 | def __await__(self): |
| 90 | yield |
| 91 | |
| 92 | @classmethod |
| 93 | def __subclasshook__(cls, C): |
| 94 | if cls is Awaitable: |
| 95 | for B in C.__mro__: |
| 96 | if "__await__" in B.__dict__: |
| 97 | if B.__dict__["__await__"]: |
| 98 | return True |
| 99 | break |
| 100 | return NotImplemented |
| 101 | |
| 102 | |
| 103 | class Coroutine(Awaitable): |
Yury Selivanov | 7544508 | 2015-05-11 22:57:16 -0400 | [diff] [blame] | 104 | |
| 105 | __slots__ = () |
| 106 | |
| 107 | @abstractmethod |
| 108 | def send(self, value): |
| 109 | """Send a value into the coroutine. |
| 110 | Return next yielded value or raise StopIteration. |
| 111 | """ |
| 112 | raise StopIteration |
| 113 | |
| 114 | @abstractmethod |
| 115 | def throw(self, typ, val=None, tb=None): |
| 116 | """Raise an exception in the coroutine. |
| 117 | Return next yielded value or raise StopIteration. |
| 118 | """ |
| 119 | if val is None: |
| 120 | if tb is None: |
| 121 | raise typ |
| 122 | val = typ() |
| 123 | if tb is not None: |
| 124 | val = val.with_traceback(tb) |
| 125 | raise val |
| 126 | |
| 127 | def close(self): |
| 128 | """Raise GeneratorExit inside coroutine. |
| 129 | """ |
| 130 | try: |
| 131 | self.throw(GeneratorExit) |
| 132 | except (GeneratorExit, StopIteration): |
| 133 | pass |
| 134 | else: |
| 135 | raise RuntimeError("coroutine ignored GeneratorExit") |
| 136 | |
Yury Selivanov | 7544508 | 2015-05-11 22:57:16 -0400 | [diff] [blame] | 137 | @classmethod |
| 138 | def __subclasshook__(cls, C): |
Yury Selivanov | 56fc614 | 2015-05-29 09:01:29 -0400 | [diff] [blame] | 139 | if cls is Coroutine: |
| 140 | mro = C.__mro__ |
| 141 | for method in ('__await__', 'send', 'throw', 'close'): |
| 142 | for base in mro: |
| 143 | if method in base.__dict__: |
| 144 | break |
| 145 | else: |
| 146 | return NotImplemented |
| 147 | return True |
Yury Selivanov | 7544508 | 2015-05-11 22:57:16 -0400 | [diff] [blame] | 148 | return NotImplemented |
| 149 | |
Yury Selivanov | 7544508 | 2015-05-11 22:57:16 -0400 | [diff] [blame] | 150 | |
Yury Selivanov | 5376ba9 | 2015-06-22 12:19:30 -0400 | [diff] [blame] | 151 | Coroutine.register(coroutine) |
| 152 | |
| 153 | |
Yury Selivanov | e0104ae | 2015-05-14 12:19:16 -0400 | [diff] [blame] | 154 | class AsyncIterable(metaclass=ABCMeta): |
| 155 | |
| 156 | __slots__ = () |
| 157 | |
| 158 | @abstractmethod |
| 159 | async def __aiter__(self): |
| 160 | return AsyncIterator() |
| 161 | |
| 162 | @classmethod |
| 163 | def __subclasshook__(cls, C): |
| 164 | if cls is AsyncIterable: |
| 165 | if any("__aiter__" in B.__dict__ for B in C.__mro__): |
| 166 | return True |
| 167 | return NotImplemented |
| 168 | |
| 169 | |
| 170 | class AsyncIterator(AsyncIterable): |
| 171 | |
| 172 | __slots__ = () |
| 173 | |
| 174 | @abstractmethod |
| 175 | async def __anext__(self): |
| 176 | """Return the next item or raise StopAsyncIteration when exhausted.""" |
| 177 | raise StopAsyncIteration |
| 178 | |
| 179 | async def __aiter__(self): |
| 180 | return self |
| 181 | |
| 182 | @classmethod |
| 183 | def __subclasshook__(cls, C): |
| 184 | if cls is AsyncIterator: |
| 185 | if (any("__anext__" in B.__dict__ for B in C.__mro__) and |
| 186 | any("__aiter__" in B.__dict__ for B in C.__mro__)): |
| 187 | return True |
| 188 | return NotImplemented |
| 189 | |
| 190 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 191 | class Iterable(metaclass=ABCMeta): |
| 192 | |
Raymond Hettinger | c46759a | 2011-03-22 11:46:25 -0700 | [diff] [blame] | 193 | __slots__ = () |
| 194 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 195 | @abstractmethod |
| 196 | def __iter__(self): |
| 197 | while False: |
| 198 | yield None |
| 199 | |
| 200 | @classmethod |
| 201 | def __subclasshook__(cls, C): |
| 202 | if cls is Iterable: |
| 203 | if any("__iter__" in B.__dict__ for B in C.__mro__): |
| 204 | return True |
| 205 | return NotImplemented |
| 206 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 207 | |
Raymond Hettinger | 74b6495 | 2008-02-09 02:53:48 +0000 | [diff] [blame] | 208 | class Iterator(Iterable): |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 209 | |
Raymond Hettinger | c46759a | 2011-03-22 11:46:25 -0700 | [diff] [blame] | 210 | __slots__ = () |
| 211 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 212 | @abstractmethod |
| 213 | def __next__(self): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 214 | 'Return the next item from the iterator. When exhausted, raise StopIteration' |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 215 | raise StopIteration |
| 216 | |
| 217 | def __iter__(self): |
| 218 | return self |
| 219 | |
| 220 | @classmethod |
| 221 | def __subclasshook__(cls, C): |
| 222 | if cls is Iterator: |
Raymond Hettinger | ead2222 | 2010-11-29 03:56:12 +0000 | [diff] [blame] | 223 | if (any("__next__" in B.__dict__ for B in C.__mro__) and |
| 224 | any("__iter__" in B.__dict__ for B in C.__mro__)): |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 225 | return True |
| 226 | return NotImplemented |
| 227 | |
Christian Heimes | f83be4e | 2007-11-28 09:44:38 +0000 | [diff] [blame] | 228 | Iterator.register(bytes_iterator) |
| 229 | Iterator.register(bytearray_iterator) |
| 230 | #Iterator.register(callable_iterator) |
| 231 | Iterator.register(dict_keyiterator) |
| 232 | Iterator.register(dict_valueiterator) |
| 233 | Iterator.register(dict_itemiterator) |
| 234 | Iterator.register(list_iterator) |
| 235 | Iterator.register(list_reverseiterator) |
| 236 | Iterator.register(range_iterator) |
| 237 | Iterator.register(set_iterator) |
| 238 | Iterator.register(str_iterator) |
| 239 | Iterator.register(tuple_iterator) |
| 240 | Iterator.register(zip_iterator) |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 241 | |
Raymond Hettinger | bd60e8d | 2015-05-09 01:07:23 -0400 | [diff] [blame] | 242 | |
Guido van Rossum | 16ca06b | 2016-04-04 10:59:29 -0700 | [diff] [blame] | 243 | class Reversible(Iterable): |
| 244 | |
| 245 | __slots__ = () |
| 246 | |
| 247 | @abstractmethod |
| 248 | def __reversed__(self): |
| 249 | return NotImplemented |
| 250 | |
| 251 | @classmethod |
| 252 | def __subclasshook__(cls, C): |
| 253 | if cls is Reversible: |
| 254 | for B in C.__mro__: |
| 255 | if "__reversed__" in B.__dict__: |
| 256 | if B.__dict__["__reversed__"] is not None: |
| 257 | return True |
| 258 | break |
| 259 | return NotImplemented |
| 260 | |
| 261 | |
Raymond Hettinger | bd60e8d | 2015-05-09 01:07:23 -0400 | [diff] [blame] | 262 | class Generator(Iterator): |
| 263 | |
| 264 | __slots__ = () |
| 265 | |
| 266 | def __next__(self): |
| 267 | """Return the next item from the generator. |
| 268 | When exhausted, raise StopIteration. |
| 269 | """ |
| 270 | return self.send(None) |
| 271 | |
| 272 | @abstractmethod |
| 273 | def send(self, value): |
| 274 | """Send a value into the generator. |
| 275 | Return next yielded value or raise StopIteration. |
| 276 | """ |
| 277 | raise StopIteration |
| 278 | |
| 279 | @abstractmethod |
| 280 | def throw(self, typ, val=None, tb=None): |
| 281 | """Raise an exception in the generator. |
| 282 | Return next yielded value or raise StopIteration. |
| 283 | """ |
| 284 | if val is None: |
| 285 | if tb is None: |
| 286 | raise typ |
| 287 | val = typ() |
| 288 | if tb is not None: |
| 289 | val = val.with_traceback(tb) |
| 290 | raise val |
| 291 | |
| 292 | def close(self): |
| 293 | """Raise GeneratorExit inside generator. |
| 294 | """ |
| 295 | try: |
| 296 | self.throw(GeneratorExit) |
| 297 | except (GeneratorExit, StopIteration): |
| 298 | pass |
| 299 | else: |
| 300 | raise RuntimeError("generator ignored GeneratorExit") |
| 301 | |
| 302 | @classmethod |
| 303 | def __subclasshook__(cls, C): |
| 304 | if cls is Generator: |
| 305 | mro = C.__mro__ |
| 306 | for method in ('__iter__', '__next__', 'send', 'throw', 'close'): |
| 307 | for base in mro: |
| 308 | if method in base.__dict__: |
| 309 | break |
| 310 | else: |
| 311 | return NotImplemented |
| 312 | return True |
| 313 | return NotImplemented |
| 314 | |
| 315 | |
| 316 | Generator.register(generator) |
| 317 | |
| 318 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 319 | class Sized(metaclass=ABCMeta): |
| 320 | |
Raymond Hettinger | c46759a | 2011-03-22 11:46:25 -0700 | [diff] [blame] | 321 | __slots__ = () |
| 322 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 323 | @abstractmethod |
| 324 | def __len__(self): |
| 325 | return 0 |
| 326 | |
| 327 | @classmethod |
| 328 | def __subclasshook__(cls, C): |
| 329 | if cls is Sized: |
| 330 | if any("__len__" in B.__dict__ for B in C.__mro__): |
| 331 | return True |
| 332 | return NotImplemented |
| 333 | |
| 334 | |
| 335 | class Container(metaclass=ABCMeta): |
| 336 | |
Raymond Hettinger | c46759a | 2011-03-22 11:46:25 -0700 | [diff] [blame] | 337 | __slots__ = () |
| 338 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 339 | @abstractmethod |
| 340 | def __contains__(self, x): |
| 341 | return False |
| 342 | |
| 343 | @classmethod |
| 344 | def __subclasshook__(cls, C): |
| 345 | if cls is Container: |
| 346 | if any("__contains__" in B.__dict__ for B in C.__mro__): |
| 347 | return True |
| 348 | return NotImplemented |
| 349 | |
| 350 | |
| 351 | class Callable(metaclass=ABCMeta): |
| 352 | |
Raymond Hettinger | c46759a | 2011-03-22 11:46:25 -0700 | [diff] [blame] | 353 | __slots__ = () |
| 354 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 355 | @abstractmethod |
Christian Heimes | 7864476 | 2008-03-04 23:39:23 +0000 | [diff] [blame] | 356 | def __call__(self, *args, **kwds): |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 357 | return False |
| 358 | |
| 359 | @classmethod |
| 360 | def __subclasshook__(cls, C): |
| 361 | if cls is Callable: |
| 362 | if any("__call__" in B.__dict__ for B in C.__mro__): |
| 363 | return True |
| 364 | return NotImplemented |
| 365 | |
| 366 | |
| 367 | ### SETS ### |
| 368 | |
| 369 | |
Raymond Hettinger | 74b6495 | 2008-02-09 02:53:48 +0000 | [diff] [blame] | 370 | class Set(Sized, Iterable, Container): |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 371 | |
| 372 | """A set is a finite, iterable container. |
| 373 | |
| 374 | This class provides concrete generic implementations of all |
| 375 | methods except for __contains__, __iter__ and __len__. |
| 376 | |
| 377 | To override the comparisons (presumably for speed, as the |
Raymond Hettinger | 11cda47 | 2014-07-03 00:31:30 +0100 | [diff] [blame] | 378 | semantics are fixed), redefine __le__ and __ge__, |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 379 | then the other operations will automatically follow suit. |
| 380 | """ |
| 381 | |
Raymond Hettinger | c46759a | 2011-03-22 11:46:25 -0700 | [diff] [blame] | 382 | __slots__ = () |
| 383 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 384 | def __le__(self, other): |
| 385 | if not isinstance(other, Set): |
| 386 | return NotImplemented |
| 387 | if len(self) > len(other): |
| 388 | return False |
| 389 | for elem in self: |
| 390 | if elem not in other: |
| 391 | return False |
| 392 | return True |
| 393 | |
| 394 | def __lt__(self, other): |
| 395 | if not isinstance(other, Set): |
| 396 | return NotImplemented |
| 397 | return len(self) < len(other) and self.__le__(other) |
| 398 | |
Raymond Hettinger | 7190942 | 2008-02-09 00:08:16 +0000 | [diff] [blame] | 399 | def __gt__(self, other): |
| 400 | if not isinstance(other, Set): |
| 401 | return NotImplemented |
Raymond Hettinger | dd5e53a | 2014-05-26 00:09:04 -0700 | [diff] [blame] | 402 | return len(self) > len(other) and self.__ge__(other) |
Raymond Hettinger | 7190942 | 2008-02-09 00:08:16 +0000 | [diff] [blame] | 403 | |
| 404 | def __ge__(self, other): |
| 405 | if not isinstance(other, Set): |
| 406 | return NotImplemented |
Raymond Hettinger | dd5e53a | 2014-05-26 00:09:04 -0700 | [diff] [blame] | 407 | if len(self) < len(other): |
| 408 | return False |
| 409 | for elem in other: |
| 410 | if elem not in self: |
| 411 | return False |
| 412 | return True |
Raymond Hettinger | 7190942 | 2008-02-09 00:08:16 +0000 | [diff] [blame] | 413 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 414 | def __eq__(self, other): |
| 415 | if not isinstance(other, Set): |
| 416 | return NotImplemented |
| 417 | return len(self) == len(other) and self.__le__(other) |
| 418 | |
| 419 | @classmethod |
| 420 | def _from_iterable(cls, it): |
Raymond Hettinger | 8284c4a | 2008-02-06 20:47:09 +0000 | [diff] [blame] | 421 | '''Construct an instance of the class from any iterable input. |
| 422 | |
| 423 | Must override this method if the class constructor signature |
Raymond Hettinger | 7aebb64 | 2008-02-09 03:25:08 +0000 | [diff] [blame] | 424 | does not accept an iterable for an input. |
Raymond Hettinger | 8284c4a | 2008-02-06 20:47:09 +0000 | [diff] [blame] | 425 | ''' |
Raymond Hettinger | 7aebb64 | 2008-02-09 03:25:08 +0000 | [diff] [blame] | 426 | return cls(it) |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 427 | |
| 428 | def __and__(self, other): |
| 429 | if not isinstance(other, Iterable): |
| 430 | return NotImplemented |
| 431 | return self._from_iterable(value for value in other if value in self) |
| 432 | |
Raymond Hettinger | dd5e53a | 2014-05-26 00:09:04 -0700 | [diff] [blame] | 433 | __rand__ = __and__ |
| 434 | |
Christian Heimes | 190d79e | 2008-01-30 11:58:22 +0000 | [diff] [blame] | 435 | def isdisjoint(self, other): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 436 | 'Return True if two sets have a null intersection.' |
Christian Heimes | 190d79e | 2008-01-30 11:58:22 +0000 | [diff] [blame] | 437 | for value in other: |
| 438 | if value in self: |
| 439 | return False |
| 440 | return True |
| 441 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 442 | def __or__(self, other): |
| 443 | if not isinstance(other, Iterable): |
| 444 | return NotImplemented |
Christian Heimes | 7864476 | 2008-03-04 23:39:23 +0000 | [diff] [blame] | 445 | chain = (e for s in (self, other) for e in s) |
| 446 | return self._from_iterable(chain) |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 447 | |
Raymond Hettinger | dd5e53a | 2014-05-26 00:09:04 -0700 | [diff] [blame] | 448 | __ror__ = __or__ |
| 449 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 450 | def __sub__(self, other): |
| 451 | if not isinstance(other, Set): |
| 452 | if not isinstance(other, Iterable): |
| 453 | return NotImplemented |
| 454 | other = self._from_iterable(other) |
| 455 | return self._from_iterable(value for value in self |
| 456 | if value not in other) |
| 457 | |
Raymond Hettinger | dd5e53a | 2014-05-26 00:09:04 -0700 | [diff] [blame] | 458 | def __rsub__(self, other): |
| 459 | if not isinstance(other, Set): |
| 460 | if not isinstance(other, Iterable): |
| 461 | return NotImplemented |
| 462 | other = self._from_iterable(other) |
| 463 | return self._from_iterable(value for value in other |
| 464 | if value not in self) |
| 465 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 466 | def __xor__(self, other): |
| 467 | if not isinstance(other, Set): |
| 468 | if not isinstance(other, Iterable): |
| 469 | return NotImplemented |
| 470 | other = self._from_iterable(other) |
| 471 | return (self - other) | (other - self) |
| 472 | |
Raymond Hettinger | dd5e53a | 2014-05-26 00:09:04 -0700 | [diff] [blame] | 473 | __rxor__ = __xor__ |
| 474 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 475 | def _hash(self): |
| 476 | """Compute the hash value of a set. |
| 477 | |
| 478 | Note that we don't define __hash__: not all sets are hashable. |
| 479 | But if you define a hashable set type, its __hash__ should |
| 480 | call this function. |
| 481 | |
| 482 | This must be compatible __eq__. |
| 483 | |
| 484 | All sets ought to compare equal if they contain the same |
| 485 | elements, regardless of how they are implemented, and |
| 486 | regardless of the order of the elements; so there's not much |
| 487 | freedom for __eq__ or __hash__. We match the algorithm used |
| 488 | by the built-in frozenset type. |
| 489 | """ |
Christian Heimes | a37d4c6 | 2007-12-04 23:02:19 +0000 | [diff] [blame] | 490 | MAX = sys.maxsize |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 491 | MASK = 2 * MAX + 1 |
| 492 | n = len(self) |
| 493 | h = 1927868237 * (n + 1) |
| 494 | h &= MASK |
| 495 | for x in self: |
| 496 | hx = hash(x) |
| 497 | h ^= (hx ^ (hx << 16) ^ 89869747) * 3644798167 |
| 498 | h &= MASK |
| 499 | h = h * 69069 + 907133923 |
| 500 | h &= MASK |
| 501 | if h > MAX: |
| 502 | h -= MASK + 1 |
| 503 | if h == -1: |
| 504 | h = 590923713 |
| 505 | return h |
| 506 | |
| 507 | Set.register(frozenset) |
| 508 | |
| 509 | |
| 510 | class MutableSet(Set): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 511 | """A mutable set is a finite, iterable container. |
| 512 | |
| 513 | This class provides concrete generic implementations of all |
| 514 | methods except for __contains__, __iter__, __len__, |
| 515 | add(), and discard(). |
| 516 | |
| 517 | To override the comparisons (presumably for speed, as the |
| 518 | semantics are fixed), all you have to do is redefine __le__ and |
| 519 | then the other operations will automatically follow suit. |
| 520 | """ |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 521 | |
Raymond Hettinger | c46759a | 2011-03-22 11:46:25 -0700 | [diff] [blame] | 522 | __slots__ = () |
| 523 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 524 | @abstractmethod |
| 525 | def add(self, value): |
Benjamin Peterson | 058e31e | 2009-01-16 03:54:08 +0000 | [diff] [blame] | 526 | """Add an element.""" |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 527 | raise NotImplementedError |
| 528 | |
| 529 | @abstractmethod |
| 530 | def discard(self, value): |
Benjamin Peterson | 058e31e | 2009-01-16 03:54:08 +0000 | [diff] [blame] | 531 | """Remove an element. Do not raise an exception if absent.""" |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 532 | raise NotImplementedError |
| 533 | |
Christian Heimes | 190d79e | 2008-01-30 11:58:22 +0000 | [diff] [blame] | 534 | def remove(self, value): |
| 535 | """Remove an element. If not a member, raise a KeyError.""" |
| 536 | if value not in self: |
| 537 | raise KeyError(value) |
| 538 | self.discard(value) |
| 539 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 540 | def pop(self): |
| 541 | """Return the popped value. Raise KeyError if empty.""" |
| 542 | it = iter(self) |
| 543 | try: |
Raymond Hettinger | ae65018 | 2009-01-28 23:33:59 +0000 | [diff] [blame] | 544 | value = next(it) |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 545 | except StopIteration: |
| 546 | raise KeyError |
| 547 | self.discard(value) |
| 548 | return value |
| 549 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 550 | def clear(self): |
| 551 | """This is slow (creates N new iterators!) but effective.""" |
| 552 | try: |
| 553 | while True: |
| 554 | self.pop() |
| 555 | except KeyError: |
| 556 | pass |
| 557 | |
Raymond Hettinger | b3d89a4 | 2011-01-12 20:37:47 +0000 | [diff] [blame] | 558 | def __ior__(self, it): |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 559 | for value in it: |
| 560 | self.add(value) |
| 561 | return self |
| 562 | |
Raymond Hettinger | b3d89a4 | 2011-01-12 20:37:47 +0000 | [diff] [blame] | 563 | def __iand__(self, it): |
Raymond Hettinger | 3f10a95 | 2009-04-01 19:05:50 +0000 | [diff] [blame] | 564 | for value in (self - it): |
| 565 | self.discard(value) |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 566 | return self |
| 567 | |
Raymond Hettinger | b3d89a4 | 2011-01-12 20:37:47 +0000 | [diff] [blame] | 568 | def __ixor__(self, it): |
Daniel Stutzbach | 31da5b2 | 2010-08-24 20:49:57 +0000 | [diff] [blame] | 569 | if it is self: |
| 570 | self.clear() |
| 571 | else: |
| 572 | if not isinstance(it, Set): |
| 573 | it = self._from_iterable(it) |
| 574 | for value in it: |
| 575 | if value in self: |
| 576 | self.discard(value) |
| 577 | else: |
| 578 | self.add(value) |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 579 | return self |
| 580 | |
Raymond Hettinger | b3d89a4 | 2011-01-12 20:37:47 +0000 | [diff] [blame] | 581 | def __isub__(self, it): |
Daniel Stutzbach | 31da5b2 | 2010-08-24 20:49:57 +0000 | [diff] [blame] | 582 | if it is self: |
| 583 | self.clear() |
| 584 | else: |
| 585 | for value in it: |
| 586 | self.discard(value) |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 587 | return self |
| 588 | |
| 589 | MutableSet.register(set) |
| 590 | |
| 591 | |
| 592 | ### MAPPINGS ### |
| 593 | |
| 594 | |
Raymond Hettinger | 74b6495 | 2008-02-09 02:53:48 +0000 | [diff] [blame] | 595 | class Mapping(Sized, Iterable, Container): |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 596 | |
Raymond Hettinger | c46759a | 2011-03-22 11:46:25 -0700 | [diff] [blame] | 597 | __slots__ = () |
| 598 | |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 599 | """A Mapping is a generic container for associating key/value |
| 600 | pairs. |
| 601 | |
| 602 | This class provides concrete generic implementations of all |
| 603 | methods except for __getitem__, __iter__, and __len__. |
| 604 | |
| 605 | """ |
| 606 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 607 | @abstractmethod |
| 608 | def __getitem__(self, key): |
| 609 | raise KeyError |
| 610 | |
| 611 | def get(self, key, default=None): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 612 | '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] | 613 | try: |
| 614 | return self[key] |
| 615 | except KeyError: |
| 616 | return default |
| 617 | |
| 618 | def __contains__(self, key): |
| 619 | try: |
| 620 | self[key] |
| 621 | except KeyError: |
| 622 | return False |
| 623 | else: |
| 624 | return True |
| 625 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 626 | def keys(self): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 627 | "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] | 628 | return KeysView(self) |
| 629 | |
| 630 | def items(self): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 631 | "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] | 632 | return ItemsView(self) |
| 633 | |
| 634 | def values(self): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 635 | "D.values() -> an object providing a view on D's values" |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 636 | return ValuesView(self) |
| 637 | |
Raymond Hettinger | b9da9bc | 2008-02-04 20:44:31 +0000 | [diff] [blame] | 638 | def __eq__(self, other): |
Benjamin Peterson | 4ad6bd5 | 2010-05-21 20:55:22 +0000 | [diff] [blame] | 639 | if not isinstance(other, Mapping): |
| 640 | return NotImplemented |
| 641 | return dict(self.items()) == dict(other.items()) |
Raymond Hettinger | b9da9bc | 2008-02-04 20:44:31 +0000 | [diff] [blame] | 642 | |
Victor Stinner | 7b17a4e | 2012-04-20 01:41:36 +0200 | [diff] [blame] | 643 | Mapping.register(mappingproxy) |
| 644 | |
Christian Heimes | 2202f87 | 2008-02-06 14:31:34 +0000 | [diff] [blame] | 645 | |
Raymond Hettinger | bfd0612 | 2008-02-09 10:04:32 +0000 | [diff] [blame] | 646 | class MappingView(Sized): |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 647 | |
Raymond Hettinger | 3170d1c | 2014-05-03 19:06:32 -0700 | [diff] [blame] | 648 | __slots__ = '_mapping', |
| 649 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 650 | def __init__(self, mapping): |
| 651 | self._mapping = mapping |
| 652 | |
| 653 | def __len__(self): |
| 654 | return len(self._mapping) |
| 655 | |
Raymond Hettinger | 89fc2b7 | 2009-02-27 07:47:32 +0000 | [diff] [blame] | 656 | def __repr__(self): |
| 657 | return '{0.__class__.__name__}({0._mapping!r})'.format(self) |
| 658 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 659 | |
| 660 | class KeysView(MappingView, Set): |
| 661 | |
Raymond Hettinger | 3170d1c | 2014-05-03 19:06:32 -0700 | [diff] [blame] | 662 | __slots__ = () |
| 663 | |
Raymond Hettinger | 9117c75 | 2010-08-22 07:44:24 +0000 | [diff] [blame] | 664 | @classmethod |
| 665 | def _from_iterable(self, it): |
| 666 | return set(it) |
| 667 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 668 | def __contains__(self, key): |
| 669 | return key in self._mapping |
| 670 | |
| 671 | def __iter__(self): |
Philip Jenvey | 4993cc0 | 2012-10-01 12:53:43 -0700 | [diff] [blame] | 672 | yield from self._mapping |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 673 | |
Christian Heimes | f83be4e | 2007-11-28 09:44:38 +0000 | [diff] [blame] | 674 | KeysView.register(dict_keys) |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 675 | |
| 676 | |
| 677 | class ItemsView(MappingView, Set): |
| 678 | |
Raymond Hettinger | 3170d1c | 2014-05-03 19:06:32 -0700 | [diff] [blame] | 679 | __slots__ = () |
| 680 | |
Raymond Hettinger | 9117c75 | 2010-08-22 07:44:24 +0000 | [diff] [blame] | 681 | @classmethod |
| 682 | def _from_iterable(self, it): |
| 683 | return set(it) |
| 684 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 685 | def __contains__(self, item): |
| 686 | key, value = item |
| 687 | try: |
| 688 | v = self._mapping[key] |
| 689 | except KeyError: |
| 690 | return False |
| 691 | else: |
Raymond Hettinger | 584e8ae | 2016-05-05 11:14:06 +0300 | [diff] [blame^] | 692 | return v is value or v == value |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 693 | |
| 694 | def __iter__(self): |
| 695 | for key in self._mapping: |
| 696 | yield (key, self._mapping[key]) |
| 697 | |
Christian Heimes | f83be4e | 2007-11-28 09:44:38 +0000 | [diff] [blame] | 698 | ItemsView.register(dict_items) |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 699 | |
| 700 | |
| 701 | class ValuesView(MappingView): |
| 702 | |
Raymond Hettinger | 3170d1c | 2014-05-03 19:06:32 -0700 | [diff] [blame] | 703 | __slots__ = () |
| 704 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 705 | def __contains__(self, value): |
| 706 | for key in self._mapping: |
Raymond Hettinger | 584e8ae | 2016-05-05 11:14:06 +0300 | [diff] [blame^] | 707 | v = self._mapping[key] |
| 708 | if v is value or v == value: |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 709 | return True |
| 710 | return False |
| 711 | |
| 712 | def __iter__(self): |
| 713 | for key in self._mapping: |
| 714 | yield self._mapping[key] |
| 715 | |
Christian Heimes | f83be4e | 2007-11-28 09:44:38 +0000 | [diff] [blame] | 716 | ValuesView.register(dict_values) |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 717 | |
| 718 | |
| 719 | class MutableMapping(Mapping): |
| 720 | |
Raymond Hettinger | c46759a | 2011-03-22 11:46:25 -0700 | [diff] [blame] | 721 | __slots__ = () |
| 722 | |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 723 | """A MutableMapping is a generic container for associating |
| 724 | key/value pairs. |
| 725 | |
| 726 | This class provides concrete generic implementations of all |
| 727 | methods except for __getitem__, __setitem__, __delitem__, |
| 728 | __iter__, and __len__. |
| 729 | |
| 730 | """ |
| 731 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 732 | @abstractmethod |
| 733 | def __setitem__(self, key, value): |
| 734 | raise KeyError |
| 735 | |
| 736 | @abstractmethod |
| 737 | def __delitem__(self, key): |
| 738 | raise KeyError |
| 739 | |
| 740 | __marker = object() |
| 741 | |
| 742 | def pop(self, key, default=__marker): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 743 | '''D.pop(k[,d]) -> v, remove specified key and return the corresponding value. |
| 744 | If key is not found, d is returned if given, otherwise KeyError is raised. |
| 745 | ''' |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 746 | try: |
| 747 | value = self[key] |
| 748 | except KeyError: |
| 749 | if default is self.__marker: |
| 750 | raise |
| 751 | return default |
| 752 | else: |
| 753 | del self[key] |
| 754 | return value |
| 755 | |
| 756 | def popitem(self): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 757 | '''D.popitem() -> (k, v), remove and return some (key, value) pair |
| 758 | as a 2-tuple; but raise KeyError if D is empty. |
| 759 | ''' |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 760 | try: |
| 761 | key = next(iter(self)) |
| 762 | except StopIteration: |
| 763 | raise KeyError |
| 764 | value = self[key] |
| 765 | del self[key] |
| 766 | return key, value |
| 767 | |
| 768 | def clear(self): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 769 | 'D.clear() -> None. Remove all items from D.' |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 770 | try: |
| 771 | while True: |
| 772 | self.popitem() |
| 773 | except KeyError: |
| 774 | pass |
| 775 | |
Mark Dickinson | b214e90 | 2010-07-11 18:53:06 +0000 | [diff] [blame] | 776 | def update(*args, **kwds): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 777 | ''' D.update([E, ]**F) -> None. Update D from mapping/iterable E and F. |
| 778 | If E present and has a .keys() method, does: for k in E: D[k] = E[k] |
| 779 | If E present and lacks .keys() method, does: for (k, v) in E: D[k] = v |
| 780 | In either case, this is followed by: for k, v in F.items(): D[k] = v |
| 781 | ''' |
Serhiy Storchaka | ae5cb21 | 2014-11-27 16:25:51 +0200 | [diff] [blame] | 782 | if not args: |
| 783 | raise TypeError("descriptor 'update' of 'MutableMapping' object " |
| 784 | "needs an argument") |
| 785 | self, *args = args |
| 786 | if len(args) > 1: |
| 787 | raise TypeError('update expected at most 1 arguments, got %d' % |
| 788 | len(args)) |
| 789 | if args: |
| 790 | other = args[0] |
| 791 | if isinstance(other, Mapping): |
| 792 | for key in other: |
| 793 | self[key] = other[key] |
| 794 | elif hasattr(other, "keys"): |
| 795 | for key in other.keys(): |
| 796 | self[key] = other[key] |
| 797 | else: |
| 798 | for key, value in other: |
| 799 | self[key] = value |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 800 | for key, value in kwds.items(): |
| 801 | self[key] = value |
| 802 | |
Raymond Hettinger | b9da9bc | 2008-02-04 20:44:31 +0000 | [diff] [blame] | 803 | def setdefault(self, key, default=None): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 804 | '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] | 805 | try: |
| 806 | return self[key] |
| 807 | except KeyError: |
| 808 | self[key] = default |
| 809 | return default |
| 810 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 811 | MutableMapping.register(dict) |
| 812 | |
| 813 | |
| 814 | ### SEQUENCES ### |
| 815 | |
| 816 | |
Guido van Rossum | 16ca06b | 2016-04-04 10:59:29 -0700 | [diff] [blame] | 817 | class Sequence(Sized, Reversible, Container): |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 818 | |
| 819 | """All the operations on a read-only sequence. |
| 820 | |
| 821 | Concrete subclasses must override __new__ or __init__, |
| 822 | __getitem__, and __len__. |
| 823 | """ |
| 824 | |
Raymond Hettinger | c46759a | 2011-03-22 11:46:25 -0700 | [diff] [blame] | 825 | __slots__ = () |
| 826 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 827 | @abstractmethod |
| 828 | def __getitem__(self, index): |
| 829 | raise IndexError |
| 830 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 831 | def __iter__(self): |
| 832 | i = 0 |
Raymond Hettinger | 7190942 | 2008-02-09 00:08:16 +0000 | [diff] [blame] | 833 | try: |
| 834 | while True: |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 835 | v = self[i] |
Raymond Hettinger | 7190942 | 2008-02-09 00:08:16 +0000 | [diff] [blame] | 836 | yield v |
| 837 | i += 1 |
| 838 | except IndexError: |
| 839 | return |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 840 | |
| 841 | def __contains__(self, value): |
| 842 | for v in self: |
Raymond Hettinger | 584e8ae | 2016-05-05 11:14:06 +0300 | [diff] [blame^] | 843 | if v is value or v == value: |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 844 | return True |
| 845 | return False |
| 846 | |
| 847 | def __reversed__(self): |
| 848 | for i in reversed(range(len(self))): |
| 849 | yield self[i] |
| 850 | |
Raymond Hettinger | ec219ba | 2015-05-22 19:29:22 -0700 | [diff] [blame] | 851 | def index(self, value, start=0, stop=None): |
| 852 | '''S.index(value, [start, [stop]]) -> integer -- return first index of value. |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 853 | Raises ValueError if the value is not present. |
| 854 | ''' |
Raymond Hettinger | ec219ba | 2015-05-22 19:29:22 -0700 | [diff] [blame] | 855 | if start is not None and start < 0: |
| 856 | start = max(len(self) + start, 0) |
| 857 | if stop is not None and stop < 0: |
| 858 | stop += len(self) |
| 859 | |
| 860 | i = start |
| 861 | while stop is None or i < stop: |
| 862 | try: |
| 863 | if self[i] == value: |
| 864 | return i |
| 865 | except IndexError: |
| 866 | break |
| 867 | i += 1 |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 868 | raise ValueError |
| 869 | |
| 870 | def count(self, value): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 871 | 'S.count(value) -> integer -- return number of occurrences of value' |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 872 | return sum(1 for v in self if v == value) |
| 873 | |
| 874 | Sequence.register(tuple) |
Guido van Rossum | 3172c5d | 2007-10-16 18:12:55 +0000 | [diff] [blame] | 875 | Sequence.register(str) |
Raymond Hettinger | 9aa53c2 | 2009-02-24 11:25:35 +0000 | [diff] [blame] | 876 | Sequence.register(range) |
Nick Coghlan | 45163cc | 2013-10-02 22:31:47 +1000 | [diff] [blame] | 877 | Sequence.register(memoryview) |
Guido van Rossum | d05eb00 | 2007-11-21 22:26:24 +0000 | [diff] [blame] | 878 | |
| 879 | |
| 880 | class ByteString(Sequence): |
| 881 | |
| 882 | """This unifies bytes and bytearray. |
| 883 | |
| 884 | XXX Should add all their methods. |
| 885 | """ |
| 886 | |
Raymond Hettinger | c46759a | 2011-03-22 11:46:25 -0700 | [diff] [blame] | 887 | __slots__ = () |
| 888 | |
Guido van Rossum | d05eb00 | 2007-11-21 22:26:24 +0000 | [diff] [blame] | 889 | ByteString.register(bytes) |
| 890 | ByteString.register(bytearray) |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 891 | |
| 892 | |
| 893 | class MutableSequence(Sequence): |
| 894 | |
Raymond Hettinger | c46759a | 2011-03-22 11:46:25 -0700 | [diff] [blame] | 895 | __slots__ = () |
| 896 | |
Guido van Rossum | 840c310 | 2013-07-25 11:55:41 -0700 | [diff] [blame] | 897 | """All the operations on a read-write sequence. |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 898 | |
| 899 | Concrete subclasses must provide __new__ or __init__, |
| 900 | __getitem__, __setitem__, __delitem__, __len__, and insert(). |
| 901 | |
| 902 | """ |
| 903 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 904 | @abstractmethod |
| 905 | def __setitem__(self, index, value): |
| 906 | raise IndexError |
| 907 | |
| 908 | @abstractmethod |
| 909 | def __delitem__(self, index): |
| 910 | raise IndexError |
| 911 | |
| 912 | @abstractmethod |
| 913 | def insert(self, index, value): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 914 | 'S.insert(index, value) -- insert value before index' |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 915 | raise IndexError |
| 916 | |
| 917 | def append(self, value): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 918 | 'S.append(value) -- append value to the end of the sequence' |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 919 | self.insert(len(self), value) |
| 920 | |
Eli Bendersky | 9479d1a | 2011-03-04 05:34:58 +0000 | [diff] [blame] | 921 | def clear(self): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 922 | 'S.clear() -> None -- remove all items from S' |
Eli Bendersky | 9479d1a | 2011-03-04 05:34:58 +0000 | [diff] [blame] | 923 | try: |
| 924 | while True: |
| 925 | self.pop() |
| 926 | except IndexError: |
| 927 | pass |
| 928 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 929 | def reverse(self): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 930 | 'S.reverse() -- reverse *IN PLACE*' |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 931 | n = len(self) |
| 932 | for i in range(n//2): |
| 933 | self[i], self[n-i-1] = self[n-i-1], self[i] |
| 934 | |
| 935 | def extend(self, values): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 936 | 'S.extend(iterable) -- extend sequence by appending elements from the iterable' |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 937 | for v in values: |
| 938 | self.append(v) |
| 939 | |
| 940 | def pop(self, index=-1): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 941 | '''S.pop([index]) -> item -- remove and return item at index (default last). |
| 942 | Raise IndexError if list is empty or index is out of range. |
| 943 | ''' |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 944 | v = self[index] |
| 945 | del self[index] |
| 946 | return v |
| 947 | |
| 948 | def remove(self, value): |
Raymond Hettinger | 153866e | 2013-03-24 15:20:29 -0700 | [diff] [blame] | 949 | '''S.remove(value) -- remove first occurrence of value. |
| 950 | Raise ValueError if the value is not present. |
| 951 | ''' |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 952 | del self[self.index(value)] |
| 953 | |
| 954 | def __iadd__(self, values): |
| 955 | self.extend(values) |
Raymond Hettinger | c384b22 | 2009-05-18 15:35:26 +0000 | [diff] [blame] | 956 | return self |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 957 | |
| 958 | MutableSequence.register(list) |
Guido van Rossum | d05eb00 | 2007-11-21 22:26:24 +0000 | [diff] [blame] | 959 | MutableSequence.register(bytearray) # Multiply inheriting, see ByteString |