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