EmbeddedPkg: Extend NvVarStoreFormattedLib LIBRARY_CLASS

[mirror_edk2.git] / AppPkg / Applications / Python / Python-2.7.10 / Lib / collections.py

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