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Diffstat (limited to 'lib/python2.7/collections.py')
| -rw-r--r-- | lib/python2.7/collections.py | 693 |
1 files changed, 0 insertions, 693 deletions
diff --git a/lib/python2.7/collections.py b/lib/python2.7/collections.py deleted file mode 100644 index af32e44..0000000 --- a/lib/python2.7/collections.py +++ /dev/null @@ -1,693 +0,0 @@ -__all__ = ['Counter', 'deque', 'defaultdict', 'namedtuple', 'OrderedDict'] -# For bootstrapping reasons, the collection ABCs are defined in _abcoll.py. -# They should however be considered an integral part of collections.py. -from _abcoll import * -import _abcoll -__all__ += _abcoll.__all__ - -from _collections import deque, defaultdict -from operator import itemgetter as _itemgetter, eq as _eq -from keyword import iskeyword as _iskeyword -import sys as _sys -import heapq as _heapq -from itertools import repeat as _repeat, chain as _chain, starmap as _starmap -from itertools import imap as _imap - -try: - from thread import get_ident as _get_ident -except ImportError: - from dummy_thread import get_ident as _get_ident - - -################################################################################ -### OrderedDict -################################################################################ - -class OrderedDict(dict): - 'Dictionary that remembers insertion order' - # An inherited dict maps keys to values. - # The inherited dict provides __getitem__, __len__, __contains__, and get. - # The remaining methods are order-aware. - # Big-O running times for all methods are the same as regular dictionaries. - - # The internal self.__map dict maps keys to links in a doubly linked list. - # The circular doubly linked list starts and ends with a sentinel element. - # The sentinel element never gets deleted (this simplifies the algorithm). - # Each link is stored as a list of length three: [PREV, NEXT, KEY]. - - def __init__(self, *args, **kwds): - '''Initialize an ordered dictionary. The signature is the same as - regular dictionaries, but keyword arguments are not recommended because - their insertion order is arbitrary. - - ''' - if len(args) > 1: - raise TypeError('expected at most 1 arguments, got %d' % len(args)) - try: - self.__root - except AttributeError: - self.__root = root = [] # sentinel node - root[:] = [root, root, None] - self.__map = {} - self.__update(*args, **kwds) - - def __setitem__(self, key, value, dict_setitem=dict.__setitem__): - 'od.__setitem__(i, y) <==> od[i]=y' - # Setting a new item creates a new link at the end of the linked list, - # and the inherited dictionary is updated with the new key/value pair. - if key not in self: - root = self.__root - last = root[0] - last[1] = root[0] = self.__map[key] = [last, root, key] - return dict_setitem(self, key, value) - - def __delitem__(self, key, dict_delitem=dict.__delitem__): - 'od.__delitem__(y) <==> del od[y]' - # Deleting an existing item uses self.__map to find the link which gets - # removed by updating the links in the predecessor and successor nodes. - dict_delitem(self, key) - link_prev, link_next, _ = self.__map.pop(key) - link_prev[1] = link_next # update link_prev[NEXT] - link_next[0] = link_prev # update link_next[PREV] - - def __iter__(self): - 'od.__iter__() <==> iter(od)' - # Traverse the linked list in order. - root = self.__root - curr = root[1] # start at the first node - while curr is not root: - yield curr[2] # yield the curr[KEY] - curr = curr[1] # move to next node - - def __reversed__(self): - 'od.__reversed__() <==> reversed(od)' - # Traverse the linked list in reverse order. - root = self.__root - curr = root[0] # start at the last node - while curr is not root: - yield curr[2] # yield the curr[KEY] - curr = curr[0] # move to previous node - - def clear(self): - 'od.clear() -> None. Remove all items from od.' - root = self.__root - root[:] = [root, root, None] - self.__map.clear() - dict.clear(self) - - # -- the following methods do not depend on the internal structure -- - - def keys(self): - 'od.keys() -> list of keys in od' - return list(self) - - def values(self): - 'od.values() -> list of values in od' - return [self[key] for key in self] - - def items(self): - 'od.items() -> list of (key, value) pairs in od' - return [(key, self[key]) for key in self] - - def iterkeys(self): - 'od.iterkeys() -> an iterator over the keys in od' - return iter(self) - - def itervalues(self): - 'od.itervalues -> an iterator over the values in od' - for k in self: - yield self[k] - - def iteritems(self): - 'od.iteritems -> an iterator over the (key, value) pairs in od' - for k in self: - yield (k, self[k]) - - update = MutableMapping.update - - __update = update # let subclasses override update without breaking __init__ - - __marker = object() - - def pop(self, key, default=__marker): - '''od.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. - - ''' - if key in self: - result = self[key] - del self[key] - return result - if default is self.__marker: - raise KeyError(key) - return default - - def setdefault(self, key, default=None): - 'od.setdefault(k[,d]) -> od.get(k,d), also set od[k]=d if k not in od' - if key in self: - return self[key] - self[key] = default - return default - - def popitem(self, last=True): - '''od.popitem() -> (k, v), return and remove a (key, value) pair. - Pairs are returned in LIFO order if last is true or FIFO order if false. - - ''' - if not self: - raise KeyError('dictionary is empty') - key = next(reversed(self) if last else iter(self)) - value = self.pop(key) - return key, value - - def __repr__(self, _repr_running={}): - 'od.__repr__() <==> repr(od)' - call_key = id(self), _get_ident() - if call_key in _repr_running: - return '...' - _repr_running[call_key] = 1 - try: - if not self: - return '%s()' % (self.__class__.__name__,) - return '%s(%r)' % (self.__class__.__name__, self.items()) - finally: - del _repr_running[call_key] - - def __reduce__(self): - 'Return state information for pickling' - items = [[k, self[k]] for k in self] - inst_dict = vars(self).copy() - for k in vars(OrderedDict()): - inst_dict.pop(k, None) - if inst_dict: - return (self.__class__, (items,), inst_dict) - return self.__class__, (items,) - - def copy(self): - 'od.copy() -> a shallow copy of od' - return self.__class__(self) - - @classmethod - def fromkeys(cls, iterable, value=None): - '''OD.fromkeys(S[, v]) -> New ordered dictionary with keys from S. - If not specified, the value defaults to None. - - ''' - self = cls() - for key in iterable: - self[key] = value - return self - - def __eq__(self, other): - '''od.__eq__(y) <==> od==y. Comparison to another OD is order-sensitive - while comparison to a regular mapping is order-insensitive. - - ''' - if isinstance(other, OrderedDict): - return dict.__eq__(self, other) and all(_imap(_eq, self, other)) - return dict.__eq__(self, other) - - def __ne__(self, other): - 'od.__ne__(y) <==> od!=y' - return not self == other - - # -- the following methods support python 3.x style dictionary views -- - - def viewkeys(self): - "od.viewkeys() -> a set-like object providing a view on od's keys" - return KeysView(self) - - def viewvalues(self): - "od.viewvalues() -> an object providing a view on od's values" - return ValuesView(self) - - def viewitems(self): - "od.viewitems() -> a set-like object providing a view on od's items" - return ItemsView(self) - - -################################################################################ -### namedtuple -################################################################################ - -_class_template = '''\ -class {typename}(tuple): - '{typename}({arg_list})' - - __slots__ = () - - _fields = {field_names!r} - - def __new__(_cls, {arg_list}): - 'Create new instance of {typename}({arg_list})' - return _tuple.__new__(_cls, ({arg_list})) - - @classmethod - def _make(cls, iterable, new=tuple.__new__, len=len): - 'Make a new {typename} object from a sequence or iterable' - result = new(cls, iterable) - if len(result) != {num_fields:d}: - raise TypeError('Expected {num_fields:d} arguments, got %d' % len(result)) - return result - - def __repr__(self): - 'Return a nicely formatted representation string' - return '{typename}({repr_fmt})' % self - - def _asdict(self): - 'Return a new OrderedDict which maps field names to their values' - return OrderedDict(zip(self._fields, self)) - - def _replace(_self, **kwds): - 'Return a new {typename} object replacing specified fields with new values' - result = _self._make(map(kwds.pop, {field_names!r}, _self)) - if kwds: - raise ValueError('Got unexpected field names: %r' % kwds.keys()) - return result - - def __getnewargs__(self): - 'Return self as a plain tuple. Used by copy and pickle.' - return tuple(self) - -{field_defs} -''' - -_repr_template = '{name}=%r' - -_field_template = '''\ - {name} = _property(_itemgetter({index:d}), doc='Alias for field number {index:d}') -''' - -def namedtuple(typename, field_names, verbose=False, rename=False): - """Returns a new subclass of tuple with named fields. - - >>> Point = namedtuple('Point', ['x', 'y']) - >>> Point.__doc__ # docstring for the new class - 'Point(x, y)' - >>> p = Point(11, y=22) # instantiate with positional args or keywords - >>> p[0] + p[1] # indexable like a plain tuple - 33 - >>> x, y = p # unpack like a regular tuple - >>> x, y - (11, 22) - >>> p.x + p.y # fields also accessable by name - 33 - >>> d = p._asdict() # convert to a dictionary - >>> d['x'] - 11 - >>> Point(**d) # convert from a dictionary - Point(x=11, y=22) - >>> p._replace(x=100) # _replace() is like str.replace() but targets named fields - Point(x=100, y=22) - - """ - - # Validate the field names. At the user's option, either generate an error - # message or automatically replace the field name with a valid name. - if isinstance(field_names, basestring): - field_names = field_names.replace(',', ' ').split() - field_names = map(str, field_names) - if rename: - seen = set() - for index, name in enumerate(field_names): - if (not all(c.isalnum() or c=='_' for c in name) - or _iskeyword(name) - or not name - or name[0].isdigit() - or name.startswith('_') - or name in seen): - field_names[index] = '_%d' % index - seen.add(name) - for name in [typename] + field_names: - if not all(c.isalnum() or c=='_' for c in name): - raise ValueError('Type names and field names can only contain ' - 'alphanumeric characters and underscores: %r' % name) - if _iskeyword(name): - raise ValueError('Type names and field names cannot be a ' - 'keyword: %r' % name) - if name[0].isdigit(): - raise ValueError('Type names and field names cannot start with ' - 'a number: %r' % name) - seen = set() - for name in field_names: - if name.startswith('_') and not rename: - raise ValueError('Field names cannot start with an underscore: ' - '%r' % name) - if name in seen: - raise ValueError('Encountered duplicate field name: %r' % name) - seen.add(name) - - # Fill-in the class template - class_definition = _class_template.format( - typename = typename, - field_names = tuple(field_names), - num_fields = len(field_names), - arg_list = repr(tuple(field_names)).replace("'", "")[1:-1], - repr_fmt = ', '.join(_repr_template.format(name=name) - for name in field_names), - field_defs = '\n'.join(_field_template.format(index=index, name=name) - for index, name in enumerate(field_names)) - ) - if verbose: - print class_definition - - # Execute the template string in a temporary namespace and support - # tracing utilities by setting a value for frame.f_globals['__name__'] - namespace = dict(_itemgetter=_itemgetter, __name__='namedtuple_%s' % typename, - OrderedDict=OrderedDict, _property=property, _tuple=tuple) - try: - exec class_definition in namespace - except SyntaxError as e: - raise SyntaxError(e.message + ':\n' + class_definition) - result = namespace[typename] - - # For pickling to work, the __module__ variable needs to be set to the frame - # where the named tuple is created. Bypass this step in enviroments where - # sys._getframe is not defined (Jython for example) or sys._getframe is not - # defined for arguments greater than 0 (IronPython). - try: - result.__module__ = _sys._getframe(1).f_globals.get('__name__', '__main__') - except (AttributeError, ValueError): - pass - - return result - - -######################################################################## -### Counter -######################################################################## - -class Counter(dict): - '''Dict subclass for counting hashable items. Sometimes called a bag - or multiset. Elements are stored as dictionary keys and their counts - are stored as dictionary values. - - >>> c = Counter('abcdeabcdabcaba') # count elements from a string - - >>> c.most_common(3) # three most common elements - [('a', 5), ('b', 4), ('c', 3)] - >>> sorted(c) # list all unique elements - ['a', 'b', 'c', 'd', 'e'] - >>> ''.join(sorted(c.elements())) # list elements with repetitions - 'aaaaabbbbcccdde' - >>> sum(c.values()) # total of all counts - 15 - - >>> c['a'] # count of letter 'a' - 5 - >>> for elem in 'shazam': # update counts from an iterable - ... c[elem] += 1 # by adding 1 to each element's count - >>> c['a'] # now there are seven 'a' - 7 - >>> del c['b'] # remove all 'b' - >>> c['b'] # now there are zero 'b' - 0 - - >>> d = Counter('simsalabim') # make another counter - >>> c.update(d) # add in the second counter - >>> c['a'] # now there are nine 'a' - 9 - - >>> c.clear() # empty the counter - >>> c - Counter() - - Note: If a count is set to zero or reduced to zero, it will remain - in the counter until the entry is deleted or the counter is cleared: - - >>> c = Counter('aaabbc') - >>> c['b'] -= 2 # reduce the count of 'b' by two - >>> c.most_common() # 'b' is still in, but its count is zero - [('a', 3), ('c', 1), ('b', 0)] - - ''' - # References: - # http://en.wikipedia.org/wiki/Multiset - # http://www.gnu.org/software/smalltalk/manual-base/html_node/Bag.html - # http://www.demo2s.com/Tutorial/Cpp/0380__set-multiset/Catalog0380__set-multiset.htm - # http://code.activestate.com/recipes/259174/ - # Knuth, TAOCP Vol. II section 4.6.3 - - def __init__(self, iterable=None, **kwds): - '''Create a new, empty Counter object. And if given, count elements - from an input iterable. Or, initialize the count from another mapping - of elements to their counts. - - >>> c = Counter() # a new, empty counter - >>> c = Counter('gallahad') # a new counter from an iterable - >>> c = Counter({'a': 4, 'b': 2}) # a new counter from a mapping - >>> c = Counter(a=4, b=2) # a new counter from keyword args - - ''' - super(Counter, self).__init__() - self.update(iterable, **kwds) - - def __missing__(self, key): - 'The count of elements not in the Counter is zero.' - # Needed so that self[missing_item] does not raise KeyError - return 0 - - def most_common(self, n=None): - '''List the n most common elements and their counts from the most - common to the least. If n is None, then list all element counts. - - >>> Counter('abcdeabcdabcaba').most_common(3) - [('a', 5), ('b', 4), ('c', 3)] - - ''' - # Emulate Bag.sortedByCount from Smalltalk - if n is None: - return sorted(self.iteritems(), key=_itemgetter(1), reverse=True) - return _heapq.nlargest(n, self.iteritems(), key=_itemgetter(1)) - - def elements(self): - '''Iterator over elements repeating each as many times as its count. - - >>> c = Counter('ABCABC') - >>> sorted(c.elements()) - ['A', 'A', 'B', 'B', 'C', 'C'] - - # Knuth's example for prime factors of 1836: 2**2 * 3**3 * 17**1 - >>> prime_factors = Counter({2: 2, 3: 3, 17: 1}) - >>> product = 1 - >>> for factor in prime_factors.elements(): # loop over factors - ... product *= factor # and multiply them - >>> product - 1836 - - Note, if an element's count has been set to zero or is a negative - number, elements() will ignore it. - - ''' - # Emulate Bag.do from Smalltalk and Multiset.begin from C++. - return _chain.from_iterable(_starmap(_repeat, self.iteritems())) - - # Override dict methods where necessary - - @classmethod - def fromkeys(cls, iterable, v=None): - # There is no equivalent method for counters because setting v=1 - # means that no element can have a count greater than one. - raise NotImplementedError( - 'Counter.fromkeys() is undefined. Use Counter(iterable) instead.') - - def update(self, iterable=None, **kwds): - '''Like dict.update() but add counts instead of replacing them. - - Source can be an iterable, a dictionary, or another Counter instance. - - >>> c = Counter('which') - >>> c.update('witch') # add elements from another iterable - >>> d = Counter('watch') - >>> c.update(d) # add elements from another counter - >>> c['h'] # four 'h' in which, witch, and watch - 4 - - ''' - # The regular dict.update() operation makes no sense here because the - # replace behavior results in the some of original untouched counts - # being mixed-in with all of the other counts for a mismash that - # doesn't have a straight-forward interpretation in most counting - # contexts. Instead, we implement straight-addition. Both the inputs - # and outputs are allowed to contain zero and negative counts. - - if iterable is not None: - if isinstance(iterable, Mapping): - if self: - self_get = self.get - for elem, count in iterable.iteritems(): - self[elem] = self_get(elem, 0) + count - else: - super(Counter, self).update(iterable) # fast path when counter is empty - else: - self_get = self.get - for elem in iterable: - self[elem] = self_get(elem, 0) + 1 - if kwds: - self.update(kwds) - - def subtract(self, iterable=None, **kwds): - '''Like dict.update() but subtracts counts instead of replacing them. - Counts can be reduced below zero. Both the inputs and outputs are - allowed to contain zero and negative counts. - - Source can be an iterable, a dictionary, or another Counter instance. - - >>> c = Counter('which') - >>> c.subtract('witch') # subtract elements from another iterable - >>> c.subtract(Counter('watch')) # subtract elements from another counter - >>> c['h'] # 2 in which, minus 1 in witch, minus 1 in watch - 0 - >>> c['w'] # 1 in which, minus 1 in witch, minus 1 in watch - -1 - - ''' - if iterable is not None: - self_get = self.get - if isinstance(iterable, Mapping): - for elem, count in iterable.items(): - self[elem] = self_get(elem, 0) - count - else: - for elem in iterable: - self[elem] = self_get(elem, 0) - 1 - if kwds: - self.subtract(kwds) - - def copy(self): - 'Return a shallow copy.' - return self.__class__(self) - - def __reduce__(self): - return self.__class__, (dict(self),) - - def __delitem__(self, elem): - 'Like dict.__delitem__() but does not raise KeyError for missing values.' - if elem in self: - super(Counter, self).__delitem__(elem) - - def __repr__(self): - if not self: - return '%s()' % self.__class__.__name__ - items = ', '.join(map('%r: %r'.__mod__, self.most_common())) - return '%s({%s})' % (self.__class__.__name__, items) - - # Multiset-style mathematical operations discussed in: - # Knuth TAOCP Volume II section 4.6.3 exercise 19 - # and at http://en.wikipedia.org/wiki/Multiset - # - # Outputs guaranteed to only include positive counts. - # - # To strip negative and zero counts, add-in an empty counter: - # c += Counter() - - def __add__(self, other): - '''Add counts from two counters. - - >>> Counter('abbb') + Counter('bcc') - Counter({'b': 4, 'c': 2, 'a': 1}) - - ''' - if not isinstance(other, Counter): - return NotImplemented - result = Counter() - for elem, count in self.items(): - newcount = count + other[elem] - if newcount > 0: - result[elem] = newcount - for elem, count in other.items(): - if elem not in self and count > 0: - result[elem] = count - return result - - def __sub__(self, other): - ''' Subtract count, but keep only results with positive counts. - - >>> Counter('abbbc') - Counter('bccd') - Counter({'b': 2, 'a': 1}) - - ''' - if not isinstance(other, Counter): - return NotImplemented - result = Counter() - for elem, count in self.items(): - newcount = count - other[elem] - if newcount > 0: - result[elem] = newcount - for elem, count in other.items(): - if elem not in self and count < 0: - result[elem] = 0 - count - return result - - def __or__(self, other): - '''Union is the maximum of value in either of the input counters. - - >>> Counter('abbb') | Counter('bcc') - Counter({'b': 3, 'c': 2, 'a': 1}) - - ''' - if not isinstance(other, Counter): - return NotImplemented - result = Counter() - for elem, count in self.items(): - other_count = other[elem] - newcount = other_count if count < other_count else count - if newcount > 0: - result[elem] = newcount - for elem, count in other.items(): - if elem not in self and count > 0: - result[elem] = count - return result - - def __and__(self, other): - ''' Intersection is the minimum of corresponding counts. - - >>> Counter('abbb') & Counter('bcc') - Counter({'b': 1}) - - ''' - if not isinstance(other, Counter): - return NotImplemented - result = Counter() - for elem, count in self.items(): - other_count = other[elem] - newcount = count if count < other_count else other_count - if newcount > 0: - result[elem] = newcount - return result - - -if __name__ == '__main__': - # verify that instances can be pickled - from cPickle import loads, dumps - Point = namedtuple('Point', 'x, y', True) - p = Point(x=10, y=20) - assert p == loads(dumps(p)) - - # test and demonstrate ability to override methods - class Point(namedtuple('Point', 'x y')): - __slots__ = () - @property - def hypot(self): - return (self.x ** 2 + self.y ** 2) ** 0.5 - def __str__(self): - return 'Point: x=%6.3f y=%6.3f hypot=%6.3f' % (self.x, self.y, self.hypot) - - for p in Point(3, 4), Point(14, 5/7.): - print p - - class Point(namedtuple('Point', 'x y')): - 'Point class with optimized _make() and _replace() without error-checking' - __slots__ = () - _make = classmethod(tuple.__new__) - def _replace(self, _map=map, **kwds): - return self._make(_map(kwds.get, ('x', 'y'), self)) - - print Point(11, 22)._replace(x=100) - - Point3D = namedtuple('Point3D', Point._fields + ('z',)) - print Point3D.__doc__ - - import doctest - TestResults = namedtuple('TestResults', 'failed attempted') - print TestResults(*doctest.testmod()) |