| # Copyright 2007 Google, Inc. All Rights Reserved. |
| # Licensed to PSF under a Contributor Agreement. |
| |
| """Abstract Base Classes (ABCs) for collections, according to PEP 3119. |
| |
| Unit tests are in test_collections. |
| """ |
| |
| from abc import ABCMeta, abstractmethod |
| import sys |
| |
| __all__ = ["Awaitable", "Coroutine", |
| "AsyncIterable", "AsyncIterator", "AsyncGenerator", |
| "Hashable", "Iterable", "Iterator", "Generator", "Reversible", |
| "Sized", "Container", "Callable", "Collection", |
| "Set", "MutableSet", |
| "Mapping", "MutableMapping", |
| "MappingView", "KeysView", "ItemsView", "ValuesView", |
| "Sequence", "MutableSequence", |
| "ByteString", |
| ] |
| |
| # This module has been renamed from collections.abc to _collections_abc to |
| # speed up interpreter startup. Some of the types such as MutableMapping are |
| # required early but collections module imports a lot of other modules. |
| # See issue #19218 |
| __name__ = "collections.abc" |
| |
| # Private list of types that we want to register with the various ABCs |
| # so that they will pass tests like: |
| # it = iter(somebytearray) |
| # assert isinstance(it, Iterable) |
| # Note: in other implementations, these types might not be distinct |
| # and they may have their own implementation specific types that |
| # are not included on this list. |
| bytes_iterator = type(iter(b'')) |
| bytearray_iterator = type(iter(bytearray())) |
| #callable_iterator = ??? |
| dict_keyiterator = type(iter({}.keys())) |
| dict_valueiterator = type(iter({}.values())) |
| dict_itemiterator = type(iter({}.items())) |
| list_iterator = type(iter([])) |
| list_reverseiterator = type(iter(reversed([]))) |
| range_iterator = type(iter(range(0))) |
| longrange_iterator = type(iter(range(1 << 1000))) |
| set_iterator = type(iter(set())) |
| str_iterator = type(iter("")) |
| tuple_iterator = type(iter(())) |
| zip_iterator = type(iter(zip())) |
| ## views ## |
| dict_keys = type({}.keys()) |
| dict_values = type({}.values()) |
| dict_items = type({}.items()) |
| ## misc ## |
| mappingproxy = type(type.__dict__) |
| generator = type((lambda: (yield))()) |
| ## coroutine ## |
| async def _coro(): pass |
| _coro = _coro() |
| coroutine = type(_coro) |
| _coro.close() # Prevent ResourceWarning |
| del _coro |
| ## asynchronous generator ## |
| async def _ag(): yield |
| _ag = _ag() |
| async_generator = type(_ag) |
| del _ag |
| |
| |
| ### ONE-TRICK PONIES ### |
| |
| def _check_methods(C, *methods): |
| mro = C.__mro__ |
| for method in methods: |
| for B in mro: |
| if method in B.__dict__: |
| if B.__dict__[method] is None: |
| return NotImplemented |
| break |
| else: |
| return NotImplemented |
| return True |
| |
| class Hashable(metaclass=ABCMeta): |
| |
| __slots__ = () |
| |
| @abstractmethod |
| def __hash__(self): |
| return 0 |
| |
| @classmethod |
| def __subclasshook__(cls, C): |
| if cls is Hashable: |
| return _check_methods(C, "__hash__") |
| return NotImplemented |
| |
| |
| class Awaitable(metaclass=ABCMeta): |
| |
| __slots__ = () |
| |
| @abstractmethod |
| def __await__(self): |
| yield |
| |
| @classmethod |
| def __subclasshook__(cls, C): |
| if cls is Awaitable: |
| return _check_methods(C, "__await__") |
| return NotImplemented |
| |
| |
| class Coroutine(Awaitable): |
| |
| __slots__ = () |
| |
| @abstractmethod |
| def send(self, value): |
| """Send a value into the coroutine. |
| Return next yielded value or raise StopIteration. |
| """ |
| raise StopIteration |
| |
| @abstractmethod |
| def throw(self, typ, val=None, tb=None): |
| """Raise an exception in the coroutine. |
| Return next yielded value or raise StopIteration. |
| """ |
| if val is None: |
| if tb is None: |
| raise typ |
| val = typ() |
| if tb is not None: |
| val = val.with_traceback(tb) |
| raise val |
| |
| def close(self): |
| """Raise GeneratorExit inside coroutine. |
| """ |
| try: |
| self.throw(GeneratorExit) |
| except (GeneratorExit, StopIteration): |
| pass |
| else: |
| raise RuntimeError("coroutine ignored GeneratorExit") |
| |
| @classmethod |
| def __subclasshook__(cls, C): |
| if cls is Coroutine: |
| return _check_methods(C, '__await__', 'send', 'throw', 'close') |
| return NotImplemented |
| |
| |
| Coroutine.register(coroutine) |
| |
| |
| class AsyncIterable(metaclass=ABCMeta): |
| |
| __slots__ = () |
| |
| @abstractmethod |
| def __aiter__(self): |
| return AsyncIterator() |
| |
| @classmethod |
| def __subclasshook__(cls, C): |
| if cls is AsyncIterable: |
| return _check_methods(C, "__aiter__") |
| return NotImplemented |
| |
| |
| class AsyncIterator(AsyncIterable): |
| |
| __slots__ = () |
| |
| @abstractmethod |
| async def __anext__(self): |
| """Return the next item or raise StopAsyncIteration when exhausted.""" |
| raise StopAsyncIteration |
| |
| def __aiter__(self): |
| return self |
| |
| @classmethod |
| def __subclasshook__(cls, C): |
| if cls is AsyncIterator: |
| return _check_methods(C, "__anext__", "__aiter__") |
| return NotImplemented |
| |
| |
| class AsyncGenerator(AsyncIterator): |
| |
| __slots__ = () |
| |
| async def __anext__(self): |
| """Return the next item from the asynchronous generator. |
| When exhausted, raise StopAsyncIteration. |
| """ |
| return await self.asend(None) |
| |
| @abstractmethod |
| async def asend(self, value): |
| """Send a value into the asynchronous generator. |
| Return next yielded value or raise StopAsyncIteration. |
| """ |
| raise StopAsyncIteration |
| |
| @abstractmethod |
| async def athrow(self, typ, val=None, tb=None): |
| """Raise an exception in the asynchronous generator. |
| Return next yielded value or raise StopAsyncIteration. |
| """ |
| if val is None: |
| if tb is None: |
| raise typ |
| val = typ() |
| if tb is not None: |
| val = val.with_traceback(tb) |
| raise val |
| |
| async def aclose(self): |
| """Raise GeneratorExit inside coroutine. |
| """ |
| try: |
| await self.athrow(GeneratorExit) |
| except (GeneratorExit, StopAsyncIteration): |
| pass |
| else: |
| raise RuntimeError("asynchronous generator ignored GeneratorExit") |
| |
| @classmethod |
| def __subclasshook__(cls, C): |
| if cls is AsyncGenerator: |
| return _check_methods(C, '__aiter__', '__anext__', |
| 'asend', 'athrow', 'aclose') |
| return NotImplemented |
| |
| |
| AsyncGenerator.register(async_generator) |
| |
| |
| class Iterable(metaclass=ABCMeta): |
| |
| __slots__ = () |
| |
| @abstractmethod |
| def __iter__(self): |
| while False: |
| yield None |
| |
| @classmethod |
| def __subclasshook__(cls, C): |
| if cls is Iterable: |
| return _check_methods(C, "__iter__") |
| return NotImplemented |
| |
| |
| class Iterator(Iterable): |
| |
| __slots__ = () |
| |
| @abstractmethod |
| def __next__(self): |
| 'Return the next item from the iterator. When exhausted, raise StopIteration' |
| raise StopIteration |
| |
| def __iter__(self): |
| return self |
| |
| @classmethod |
| def __subclasshook__(cls, C): |
| if cls is Iterator: |
| return _check_methods(C, '__iter__', '__next__') |
| return NotImplemented |
| |
| Iterator.register(bytes_iterator) |
| Iterator.register(bytearray_iterator) |
| #Iterator.register(callable_iterator) |
| Iterator.register(dict_keyiterator) |
| Iterator.register(dict_valueiterator) |
| Iterator.register(dict_itemiterator) |
| Iterator.register(list_iterator) |
| Iterator.register(list_reverseiterator) |
| Iterator.register(range_iterator) |
| Iterator.register(longrange_iterator) |
| Iterator.register(set_iterator) |
| Iterator.register(str_iterator) |
| Iterator.register(tuple_iterator) |
| Iterator.register(zip_iterator) |
| |
| |
| class Reversible(Iterable): |
| |
| __slots__ = () |
| |
| @abstractmethod |
| def __reversed__(self): |
| while False: |
| yield None |
| |
| @classmethod |
| def __subclasshook__(cls, C): |
| if cls is Reversible: |
| return _check_methods(C, "__reversed__", "__iter__") |
| return NotImplemented |
| |
| |
| class Generator(Iterator): |
| |
| __slots__ = () |
| |
| def __next__(self): |
| """Return the next item from the generator. |
| When exhausted, raise StopIteration. |
| """ |
| return self.send(None) |
| |
| @abstractmethod |
| def send(self, value): |
| """Send a value into the generator. |
| Return next yielded value or raise StopIteration. |
| """ |
| raise StopIteration |
| |
| @abstractmethod |
| def throw(self, typ, val=None, tb=None): |
| """Raise an exception in the generator. |
| Return next yielded value or raise StopIteration. |
| """ |
| if val is None: |
| if tb is None: |
| raise typ |
| val = typ() |
| if tb is not None: |
| val = val.with_traceback(tb) |
| raise val |
| |
| def close(self): |
| """Raise GeneratorExit inside generator. |
| """ |
| try: |
| self.throw(GeneratorExit) |
| except (GeneratorExit, StopIteration): |
| pass |
| else: |
| raise RuntimeError("generator ignored GeneratorExit") |
| |
| @classmethod |
| def __subclasshook__(cls, C): |
| if cls is Generator: |
| return _check_methods(C, '__iter__', '__next__', |
| 'send', 'throw', 'close') |
| return NotImplemented |
| |
| Generator.register(generator) |
| |
| |
| class Sized(metaclass=ABCMeta): |
| |
| __slots__ = () |
| |
| @abstractmethod |
| def __len__(self): |
| return 0 |
| |
| @classmethod |
| def __subclasshook__(cls, C): |
| if cls is Sized: |
| return _check_methods(C, "__len__") |
| return NotImplemented |
| |
| |
| class Container(metaclass=ABCMeta): |
| |
| __slots__ = () |
| |
| @abstractmethod |
| def __contains__(self, x): |
| return False |
| |
| @classmethod |
| def __subclasshook__(cls, C): |
| if cls is Container: |
| return _check_methods(C, "__contains__") |
| return NotImplemented |
| |
| class Collection(Sized, Iterable, Container): |
| |
| __slots__ = () |
| |
| @classmethod |
| def __subclasshook__(cls, C): |
| if cls is Collection: |
| return _check_methods(C, "__len__", "__iter__", "__contains__") |
| return NotImplemented |
| |
| class Callable(metaclass=ABCMeta): |
| |
| __slots__ = () |
| |
| @abstractmethod |
| def __call__(self, *args, **kwds): |
| return False |
| |
| @classmethod |
| def __subclasshook__(cls, C): |
| if cls is Callable: |
| return _check_methods(C, "__call__") |
| return NotImplemented |
| |
| |
| ### SETS ### |
| |
| |
| class Set(Collection): |
| |
| """A set is a finite, iterable container. |
| |
| This class provides concrete generic implementations of all |
| methods except for __contains__, __iter__ and __len__. |
| |
| To override the comparisons (presumably for speed, as the |
| semantics are fixed), redefine __le__ and __ge__, |
| then the other operations will automatically follow suit. |
| """ |
| |
| __slots__ = () |
| |
| def __le__(self, other): |
| if not isinstance(other, Set): |
| return NotImplemented |
| if len(self) > len(other): |
| return False |
| for elem in self: |
| if elem not in other: |
| return False |
| return True |
| |
| def __lt__(self, other): |
| if not isinstance(other, Set): |
| return NotImplemented |
| return len(self) < len(other) and self.__le__(other) |
| |
| def __gt__(self, other): |
| if not isinstance(other, Set): |
| return NotImplemented |
| return len(self) > len(other) and self.__ge__(other) |
| |
| def __ge__(self, other): |
| if not isinstance(other, Set): |
| return NotImplemented |
| if len(self) < len(other): |
| return False |
| for elem in other: |
| if elem not in self: |
| return False |
| return True |
| |
| def __eq__(self, other): |
| if not isinstance(other, Set): |
| return NotImplemented |
| return len(self) == len(other) and self.__le__(other) |
| |
| @classmethod |
| def _from_iterable(cls, it): |
| '''Construct an instance of the class from any iterable input. |
| |
| Must override this method if the class constructor signature |
| does not accept an iterable for an input. |
| ''' |
| return cls(it) |
| |
| def __and__(self, other): |
| if not isinstance(other, Iterable): |
| return NotImplemented |
| return self._from_iterable(value for value in other if value in self) |
| |
| __rand__ = __and__ |
| |
| def isdisjoint(self, other): |
| 'Return True if two sets have a null intersection.' |
| for value in other: |
| if value in self: |
| return False |
| return True |
| |
| def __or__(self, other): |
| if not isinstance(other, Iterable): |
| return NotImplemented |
| chain = (e for s in (self, other) for e in s) |
| return self._from_iterable(chain) |
| |
| __ror__ = __or__ |
| |
| def __sub__(self, other): |
| if not isinstance(other, Set): |
| if not isinstance(other, Iterable): |
| return NotImplemented |
| other = self._from_iterable(other) |
| return self._from_iterable(value for value in self |
| if value not in other) |
| |
| def __rsub__(self, other): |
| if not isinstance(other, Set): |
| if not isinstance(other, Iterable): |
| return NotImplemented |
| other = self._from_iterable(other) |
| return self._from_iterable(value for value in other |
| if value not in self) |
| |
| def __xor__(self, other): |
| if not isinstance(other, Set): |
| if not isinstance(other, Iterable): |
| return NotImplemented |
| other = self._from_iterable(other) |
| return (self - other) | (other - self) |
| |
| __rxor__ = __xor__ |
| |
| def _hash(self): |
| """Compute the hash value of a set. |
| |
| Note that we don't define __hash__: not all sets are hashable. |
| But if you define a hashable set type, its __hash__ should |
| call this function. |
| |
| This must be compatible __eq__. |
| |
| All sets ought to compare equal if they contain the same |
| elements, regardless of how they are implemented, and |
| regardless of the order of the elements; so there's not much |
| freedom for __eq__ or __hash__. We match the algorithm used |
| by the built-in frozenset type. |
| """ |
| MAX = sys.maxsize |
| MASK = 2 * MAX + 1 |
| n = len(self) |
| h = 1927868237 * (n + 1) |
| h &= MASK |
| for x in self: |
| hx = hash(x) |
| h ^= (hx ^ (hx << 16) ^ 89869747) * 3644798167 |
| h &= MASK |
| h = h * 69069 + 907133923 |
| h &= MASK |
| if h > MAX: |
| h -= MASK + 1 |
| if h == -1: |
| h = 590923713 |
| return h |
| |
| Set.register(frozenset) |
| |
| |
| class MutableSet(Set): |
| """A mutable set is a finite, iterable container. |
| |
| This class provides concrete generic implementations of all |
| methods except for __contains__, __iter__, __len__, |
| add(), and discard(). |
| |
| To override the comparisons (presumably for speed, as the |
| semantics are fixed), all you have to do is redefine __le__ and |
| then the other operations will automatically follow suit. |
| """ |
| |
| __slots__ = () |
| |
| @abstractmethod |
| def add(self, value): |
| """Add an element.""" |
| raise NotImplementedError |
| |
| @abstractmethod |
| def discard(self, value): |
| """Remove an element. Do not raise an exception if absent.""" |
| raise NotImplementedError |
| |
| def remove(self, value): |
| """Remove an element. If not a member, raise a KeyError.""" |
| if value not in self: |
| raise KeyError(value) |
| self.discard(value) |
| |
| def pop(self): |
| """Return the popped value. Raise KeyError if empty.""" |
| it = iter(self) |
| try: |
| value = next(it) |
| except StopIteration: |
| raise KeyError from None |
| self.discard(value) |
| return value |
| |
| def clear(self): |
| """This is slow (creates N new iterators!) but effective.""" |
| try: |
| while True: |
| self.pop() |
| except KeyError: |
| pass |
| |
| def __ior__(self, it): |
| for value in it: |
| self.add(value) |
| return self |
| |
| def __iand__(self, it): |
| for value in (self - it): |
| self.discard(value) |
| return self |
| |
| def __ixor__(self, it): |
| if it is self: |
| self.clear() |
| else: |
| if not isinstance(it, Set): |
| it = self._from_iterable(it) |
| for value in it: |
| if value in self: |
| self.discard(value) |
| else: |
| self.add(value) |
| return self |
| |
| def __isub__(self, it): |
| if it is self: |
| self.clear() |
| else: |
| for value in it: |
| self.discard(value) |
| return self |
| |
| MutableSet.register(set) |
| |
| |
| ### MAPPINGS ### |
| |
| |
| class Mapping(Collection): |
| |
| __slots__ = () |
| |
| """A Mapping is a generic container for associating key/value |
| pairs. |
| |
| This class provides concrete generic implementations of all |
| methods except for __getitem__, __iter__, and __len__. |
| |
| """ |
| |
| @abstractmethod |
| def __getitem__(self, key): |
| raise KeyError |
| |
| def get(self, key, default=None): |
| 'D.get(k[,d]) -> D[k] if k in D, else d. d defaults to None.' |
| try: |
| return self[key] |
| except KeyError: |
| return default |
| |
| def __contains__(self, key): |
| try: |
| self[key] |
| except KeyError: |
| return False |
| else: |
| return True |
| |
| def keys(self): |
| "D.keys() -> a set-like object providing a view on D's keys" |
| return KeysView(self) |
| |
| def items(self): |
| "D.items() -> a set-like object providing a view on D's items" |
| return ItemsView(self) |
| |
| def values(self): |
| "D.values() -> an object providing a view on D's values" |
| return ValuesView(self) |
| |
| def __eq__(self, other): |
| if not isinstance(other, Mapping): |
| return NotImplemented |
| return dict(self.items()) == dict(other.items()) |
| |
| __reversed__ = None |
| |
| Mapping.register(mappingproxy) |
| |
| |
| class MappingView(Sized): |
| |
| __slots__ = '_mapping', |
| |
| def __init__(self, mapping): |
| self._mapping = mapping |
| |
| def __len__(self): |
| return len(self._mapping) |
| |
| def __repr__(self): |
| return '{0.__class__.__name__}({0._mapping!r})'.format(self) |
| |
| |
| class KeysView(MappingView, Set): |
| |
| __slots__ = () |
| |
| @classmethod |
| def _from_iterable(self, it): |
| return set(it) |
| |
| def __contains__(self, key): |
| return key in self._mapping |
| |
| def __iter__(self): |
| yield from self._mapping |
| |
| KeysView.register(dict_keys) |
| |
| |
| class ItemsView(MappingView, Set): |
| |
| __slots__ = () |
| |
| @classmethod |
| def _from_iterable(self, it): |
| return set(it) |
| |
| def __contains__(self, item): |
| key, value = item |
| try: |
| v = self._mapping[key] |
| except KeyError: |
| return False |
| else: |
| return v is value or v == value |
| |
| def __iter__(self): |
| for key in self._mapping: |
| yield (key, self._mapping[key]) |
| |
| ItemsView.register(dict_items) |
| |
| |
| class ValuesView(MappingView): |
| |
| __slots__ = () |
| |
| def __contains__(self, value): |
| for key in self._mapping: |
| v = self._mapping[key] |
| if v is value or v == value: |
| return True |
| return False |
| |
| def __iter__(self): |
| for key in self._mapping: |
| yield self._mapping[key] |
| |
| ValuesView.register(dict_values) |
| |
| |
| class MutableMapping(Mapping): |
| |
| __slots__ = () |
| |
| """A MutableMapping is a generic container for associating |
| key/value pairs. |
| |
| This class provides concrete generic implementations of all |
| methods except for __getitem__, __setitem__, __delitem__, |
| __iter__, and __len__. |
| |
| """ |
| |
| @abstractmethod |
| def __setitem__(self, key, value): |
| raise KeyError |
| |
| @abstractmethod |
| def __delitem__(self, key): |
| raise KeyError |
| |
| __marker = object() |
| |
| def pop(self, key, default=__marker): |
| '''D.pop(k[,d]) -> v, remove specified key and return the corresponding value. |
| If key is not found, d is returned if given, otherwise KeyError is raised. |
| ''' |
| try: |
| value = self[key] |
| except KeyError: |
| if default is self.__marker: |
| raise |
| return default |
| else: |
| del self[key] |
| return value |
| |
| def popitem(self): |
| '''D.popitem() -> (k, v), remove and return some (key, value) pair |
| as a 2-tuple; but raise KeyError if D is empty. |
| ''' |
| try: |
| key = next(iter(self)) |
| except StopIteration: |
| raise KeyError from None |
| value = self[key] |
| del self[key] |
| return key, value |
| |
| def clear(self): |
| 'D.clear() -> None. Remove all items from D.' |
| try: |
| while True: |
| self.popitem() |
| except KeyError: |
| pass |
| |
| def update(*args, **kwds): |
| ''' D.update([E, ]**F) -> None. Update D from mapping/iterable E and F. |
| If E present and has a .keys() method, does: for k in E: D[k] = E[k] |
| If E present and lacks .keys() method, does: for (k, v) in E: D[k] = v |
| In either case, this is followed by: for k, v in F.items(): D[k] = v |
| ''' |
| if not args: |
| raise TypeError("descriptor 'update' of 'MutableMapping' object " |
| "needs an argument") |
| self, *args = args |
| if len(args) > 1: |
| raise TypeError('update expected at most 1 arguments, got %d' % |
| len(args)) |
| if args: |
| other = args[0] |
| if isinstance(other, Mapping): |
| for key in other: |
| self[key] = other[key] |
| elif hasattr(other, "keys"): |
| for key in other.keys(): |
| self[key] = other[key] |
| else: |
| for key, value in other: |
| self[key] = value |
| for key, value in kwds.items(): |
| self[key] = value |
| |
| def setdefault(self, key, default=None): |
| 'D.setdefault(k[,d]) -> D.get(k,d), also set D[k]=d if k not in D' |
| try: |
| return self[key] |
| except KeyError: |
| self[key] = default |
| return default |
| |
| MutableMapping.register(dict) |
| |
| |
| ### SEQUENCES ### |
| |
| |
| class Sequence(Reversible, Collection): |
| |
| """All the operations on a read-only sequence. |
| |
| Concrete subclasses must override __new__ or __init__, |
| __getitem__, and __len__. |
| """ |
| |
| __slots__ = () |
| |
| @abstractmethod |
| def __getitem__(self, index): |
| raise IndexError |
| |
| def __iter__(self): |
| i = 0 |
| try: |
| while True: |
| v = self[i] |
| yield v |
| i += 1 |
| except IndexError: |
| return |
| |
| def __contains__(self, value): |
| for v in self: |
| if v is value or v == value: |
| return True |
| return False |
| |
| def __reversed__(self): |
| for i in reversed(range(len(self))): |
| yield self[i] |
| |
| def index(self, value, start=0, stop=None): |
| '''S.index(value, [start, [stop]]) -> integer -- return first index of value. |
| Raises ValueError if the value is not present. |
| ''' |
| if start is not None and start < 0: |
| start = max(len(self) + start, 0) |
| if stop is not None and stop < 0: |
| stop += len(self) |
| |
| i = start |
| while stop is None or i < stop: |
| try: |
| v = self[i] |
| if v is value or v == value: |
| return i |
| except IndexError: |
| break |
| i += 1 |
| raise ValueError |
| |
| def count(self, value): |
| 'S.count(value) -> integer -- return number of occurrences of value' |
| return sum(1 for v in self if v is value or v == value) |
| |
| Sequence.register(tuple) |
| Sequence.register(str) |
| Sequence.register(range) |
| Sequence.register(memoryview) |
| |
| |
| class ByteString(Sequence): |
| |
| """This unifies bytes and bytearray. |
| |
| XXX Should add all their methods. |
| """ |
| |
| __slots__ = () |
| |
| ByteString.register(bytes) |
| ByteString.register(bytearray) |
| |
| |
| class MutableSequence(Sequence): |
| |
| __slots__ = () |
| |
| """All the operations on a read-write sequence. |
| |
| Concrete subclasses must provide __new__ or __init__, |
| __getitem__, __setitem__, __delitem__, __len__, and insert(). |
| |
| """ |
| |
| @abstractmethod |
| def __setitem__(self, index, value): |
| raise IndexError |
| |
| @abstractmethod |
| def __delitem__(self, index): |
| raise IndexError |
| |
| @abstractmethod |
| def insert(self, index, value): |
| 'S.insert(index, value) -- insert value before index' |
| raise IndexError |
| |
| def append(self, value): |
| 'S.append(value) -- append value to the end of the sequence' |
| self.insert(len(self), value) |
| |
| def clear(self): |
| 'S.clear() -> None -- remove all items from S' |
| try: |
| while True: |
| self.pop() |
| except IndexError: |
| pass |
| |
| def reverse(self): |
| 'S.reverse() -- reverse *IN PLACE*' |
| n = len(self) |
| for i in range(n//2): |
| self[i], self[n-i-1] = self[n-i-1], self[i] |
| |
| def extend(self, values): |
| 'S.extend(iterable) -- extend sequence by appending elements from the iterable' |
| for v in values: |
| self.append(v) |
| |
| def pop(self, index=-1): |
| '''S.pop([index]) -> item -- remove and return item at index (default last). |
| Raise IndexError if list is empty or index is out of range. |
| ''' |
| v = self[index] |
| del self[index] |
| return v |
| |
| def remove(self, value): |
| '''S.remove(value) -- remove first occurrence of value. |
| Raise ValueError if the value is not present. |
| ''' |
| del self[self.index(value)] |
| |
| def __iadd__(self, values): |
| self.extend(values) |
| return self |
| |
| MutableSequence.register(list) |
| MutableSequence.register(bytearray) # Multiply inheriting, see ByteString |