mirror of
https://github.com/python/cpython.git
synced 2024-12-15 04:44:47 +08:00
51b401bbe1
The concrete types are for internal use (registration). We are not trying to resurrect the types module in collections.
609 lines
15 KiB
Python
609 lines
15 KiB
Python
# Copyright 2007 Google, Inc. All Rights Reserved.
|
|
# Licensed to PSF under a Contributor Agreement.
|
|
|
|
"""Abstract Base Classes (ABCs) for collections, according to PEP 3119.
|
|
|
|
DON'T USE THIS MODULE DIRECTLY! The classes here should be imported
|
|
via collections; they are defined here only to alleviate certain
|
|
bootstrapping issues. Unit tests are in test_collections.
|
|
"""
|
|
|
|
from abc import ABCMeta, abstractmethod
|
|
import sys
|
|
|
|
__all__ = ["Hashable", "Iterable", "Iterator",
|
|
"Sized", "Container", "Callable",
|
|
"Set", "MutableSet",
|
|
"Mapping", "MutableMapping",
|
|
"MappingView", "KeysView", "ItemsView", "ValuesView",
|
|
"Sequence", "MutableSequence",
|
|
"ByteString",
|
|
]
|
|
|
|
|
|
### collection related types which are not exposed through builtin ###
|
|
## iterators ##
|
|
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)))
|
|
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 ##
|
|
dict_proxy = type(type.__dict__)
|
|
|
|
|
|
### ONE-TRICK PONIES ###
|
|
|
|
class Hashable(metaclass=ABCMeta):
|
|
|
|
@abstractmethod
|
|
def __hash__(self):
|
|
return 0
|
|
|
|
@classmethod
|
|
def __subclasshook__(cls, C):
|
|
if cls is Hashable:
|
|
for B in C.__mro__:
|
|
if "__hash__" in B.__dict__:
|
|
if B.__dict__["__hash__"]:
|
|
return True
|
|
break
|
|
return NotImplemented
|
|
|
|
|
|
class Iterable(metaclass=ABCMeta):
|
|
|
|
@abstractmethod
|
|
def __iter__(self):
|
|
while False:
|
|
yield None
|
|
|
|
@classmethod
|
|
def __subclasshook__(cls, C):
|
|
if cls is Iterable:
|
|
if any("__iter__" in B.__dict__ for B in C.__mro__):
|
|
return True
|
|
return NotImplemented
|
|
|
|
|
|
class Iterator(Iterable):
|
|
|
|
@abstractmethod
|
|
def __next__(self):
|
|
raise StopIteration
|
|
|
|
def __iter__(self):
|
|
return self
|
|
|
|
@classmethod
|
|
def __subclasshook__(cls, C):
|
|
if cls is Iterator:
|
|
if any("__next__" in B.__dict__ for B in C.__mro__):
|
|
return True
|
|
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(set_iterator)
|
|
Iterator.register(str_iterator)
|
|
Iterator.register(tuple_iterator)
|
|
Iterator.register(zip_iterator)
|
|
|
|
class Sized(metaclass=ABCMeta):
|
|
|
|
@abstractmethod
|
|
def __len__(self):
|
|
return 0
|
|
|
|
@classmethod
|
|
def __subclasshook__(cls, C):
|
|
if cls is Sized:
|
|
if any("__len__" in B.__dict__ for B in C.__mro__):
|
|
return True
|
|
return NotImplemented
|
|
|
|
|
|
class Container(metaclass=ABCMeta):
|
|
|
|
@abstractmethod
|
|
def __contains__(self, x):
|
|
return False
|
|
|
|
@classmethod
|
|
def __subclasshook__(cls, C):
|
|
if cls is Container:
|
|
if any("__contains__" in B.__dict__ for B in C.__mro__):
|
|
return True
|
|
return NotImplemented
|
|
|
|
|
|
class Callable(metaclass=ABCMeta):
|
|
|
|
@abstractmethod
|
|
def __call__(self, *args, **kwds):
|
|
return False
|
|
|
|
@classmethod
|
|
def __subclasshook__(cls, C):
|
|
if cls is Callable:
|
|
if any("__call__" in B.__dict__ for B in C.__mro__):
|
|
return True
|
|
return NotImplemented
|
|
|
|
|
|
### SETS ###
|
|
|
|
|
|
class Set(Sized, Iterable, Container):
|
|
|
|
"""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), all you have to do is redefine __le__ and
|
|
then the other operations will automatically follow suit.
|
|
"""
|
|
|
|
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 other < self
|
|
|
|
def __ge__(self, other):
|
|
if not isinstance(other, Set):
|
|
return NotImplemented
|
|
return other <= self
|
|
|
|
def __eq__(self, other):
|
|
if not isinstance(other, Set):
|
|
return NotImplemented
|
|
return len(self) == len(other) and self.__le__(other)
|
|
|
|
def __ne__(self, other):
|
|
return not (self == 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)
|
|
|
|
def isdisjoint(self, other):
|
|
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)
|
|
|
|
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 __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)
|
|
|
|
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):
|
|
|
|
@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
|
|
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: Iterable):
|
|
for value in it:
|
|
self.add(value)
|
|
return self
|
|
|
|
def __iand__(self, it: Iterable):
|
|
for value in (self - it):
|
|
self.discard(value)
|
|
return self
|
|
|
|
def __ixor__(self, it: Iterable):
|
|
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: Iterable):
|
|
for value in it:
|
|
self.discard(value)
|
|
return self
|
|
|
|
MutableSet.register(set)
|
|
|
|
|
|
### MAPPINGS ###
|
|
|
|
|
|
class Mapping(Sized, Iterable, Container):
|
|
|
|
@abstractmethod
|
|
def __getitem__(self, key):
|
|
raise KeyError
|
|
|
|
def get(self, key, default=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):
|
|
return KeysView(self)
|
|
|
|
def items(self):
|
|
return ItemsView(self)
|
|
|
|
def values(self):
|
|
return ValuesView(self)
|
|
|
|
def __eq__(self, other):
|
|
if not isinstance(other, Mapping):
|
|
return NotImplemented
|
|
return dict(self.items()) == dict(other.items())
|
|
|
|
def __ne__(self, other):
|
|
return not (self == other)
|
|
|
|
|
|
class MappingView(Sized):
|
|
|
|
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):
|
|
|
|
def __contains__(self, key):
|
|
return key in self._mapping
|
|
|
|
def __iter__(self):
|
|
for key in self._mapping:
|
|
yield key
|
|
|
|
KeysView.register(dict_keys)
|
|
|
|
|
|
class ItemsView(MappingView, Set):
|
|
|
|
def __contains__(self, item):
|
|
key, value = item
|
|
try:
|
|
v = self._mapping[key]
|
|
except KeyError:
|
|
return False
|
|
else:
|
|
return v == value
|
|
|
|
def __iter__(self):
|
|
for key in self._mapping:
|
|
yield (key, self._mapping[key])
|
|
|
|
ItemsView.register(dict_items)
|
|
|
|
|
|
class ValuesView(MappingView):
|
|
|
|
def __contains__(self, value):
|
|
for key in self._mapping:
|
|
if value == self._mapping[key]:
|
|
return True
|
|
return False
|
|
|
|
def __iter__(self):
|
|
for key in self._mapping:
|
|
yield self._mapping[key]
|
|
|
|
ValuesView.register(dict_values)
|
|
|
|
|
|
class MutableMapping(Mapping):
|
|
|
|
@abstractmethod
|
|
def __setitem__(self, key, value):
|
|
raise KeyError
|
|
|
|
@abstractmethod
|
|
def __delitem__(self, key):
|
|
raise KeyError
|
|
|
|
__marker = object()
|
|
|
|
def pop(self, key, default=__marker):
|
|
try:
|
|
value = self[key]
|
|
except KeyError:
|
|
if default is self.__marker:
|
|
raise
|
|
return default
|
|
else:
|
|
del self[key]
|
|
return value
|
|
|
|
def popitem(self):
|
|
try:
|
|
key = next(iter(self))
|
|
except StopIteration:
|
|
raise KeyError
|
|
value = self[key]
|
|
del self[key]
|
|
return key, value
|
|
|
|
def clear(self):
|
|
try:
|
|
while True:
|
|
self.popitem()
|
|
except KeyError:
|
|
pass
|
|
|
|
def update(*args, **kwds):
|
|
if len(args) > 2:
|
|
raise TypeError("update() takes at most 2 positional "
|
|
"arguments ({} given)".format(len(args)))
|
|
elif not args:
|
|
raise TypeError("update() takes at least 1 argument (0 given)")
|
|
self = args[0]
|
|
other = args[1] if len(args) >= 2 else ()
|
|
|
|
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):
|
|
try:
|
|
return self[key]
|
|
except KeyError:
|
|
self[key] = default
|
|
return default
|
|
|
|
MutableMapping.register(dict)
|
|
|
|
|
|
### SEQUENCES ###
|
|
|
|
|
|
class Sequence(Sized, Iterable, Container):
|
|
|
|
"""All the operations on a read-only sequence.
|
|
|
|
Concrete subclasses must override __new__ or __init__,
|
|
__getitem__, and __len__.
|
|
"""
|
|
|
|
@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 == value:
|
|
return True
|
|
return False
|
|
|
|
def __reversed__(self):
|
|
for i in reversed(range(len(self))):
|
|
yield self[i]
|
|
|
|
def index(self, value):
|
|
for i, v in enumerate(self):
|
|
if v == value:
|
|
return i
|
|
raise ValueError
|
|
|
|
def count(self, value):
|
|
return sum(1 for v in self if v == value)
|
|
|
|
Sequence.register(tuple)
|
|
Sequence.register(str)
|
|
Sequence.register(range)
|
|
|
|
|
|
class ByteString(Sequence):
|
|
|
|
"""This unifies bytes and bytearray.
|
|
|
|
XXX Should add all their methods.
|
|
"""
|
|
|
|
ByteString.register(bytes)
|
|
ByteString.register(bytearray)
|
|
|
|
|
|
class MutableSequence(Sequence):
|
|
|
|
@abstractmethod
|
|
def __setitem__(self, index, value):
|
|
raise IndexError
|
|
|
|
@abstractmethod
|
|
def __delitem__(self, index):
|
|
raise IndexError
|
|
|
|
@abstractmethod
|
|
def insert(self, index, value):
|
|
raise IndexError
|
|
|
|
def append(self, value):
|
|
self.insert(len(self), value)
|
|
|
|
def reverse(self):
|
|
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):
|
|
for v in values:
|
|
self.append(v)
|
|
|
|
def pop(self, index=-1):
|
|
v = self[index]
|
|
del self[index]
|
|
return v
|
|
|
|
def remove(self, value):
|
|
del self[self.index(value)]
|
|
|
|
def __iadd__(self, values):
|
|
self.extend(values)
|
|
return self
|
|
|
|
MutableSequence.register(list)
|
|
MutableSequence.register(bytearray) # Multiply inheriting, see ByteString
|