add ydb deps

2 files changed, 1579 insertions, 0 deletions

diff --git a/contrib/tools/python3/src/Lib/collections/__init__.py b/contrib/tools/python3/src/Lib/collections/__init__.py
new file mode 100644
index 0000000000..69398ac116
--- /dev/null
+++ b/contrib/tools/python3/src/Lib/collections/__init__.py
@@ -0,0 +1,1576 @@
+'''This module implements specialized container datatypes providing
+alternatives to Python's general purpose built-in containers, dict,
+list, set, and tuple.
+
+* namedtuple   factory function for creating tuple subclasses with named fields
+* deque        list-like container with fast appends and pops on either end
+* ChainMap     dict-like class for creating a single view of multiple mappings
+* Counter      dict subclass for counting hashable objects
+* OrderedDict  dict subclass that remembers the order entries were added
+* defaultdict  dict subclass that calls a factory function to supply missing values
+* UserDict     wrapper around dictionary objects for easier dict subclassing
+* UserList     wrapper around list objects for easier list subclassing
+* UserString   wrapper around string objects for easier string subclassing
+
+'''
+
+__all__ = [
+    'ChainMap',
+    'Counter',
+    'OrderedDict',
+    'UserDict',
+    'UserList',
+    'UserString',
+    'defaultdict',
+    'deque',
+    'namedtuple',
+]
+
+import _collections_abc
+import sys as _sys
+
+from itertools import chain as _chain
+from itertools import repeat as _repeat
+from itertools import starmap as _starmap
+from keyword import iskeyword as _iskeyword
+from operator import eq as _eq
+from operator import itemgetter as _itemgetter
+from reprlib import recursive_repr as _recursive_repr
+from _weakref import proxy as _proxy
+
+try:
+    from _collections import deque
+except ImportError:
+    pass
+else:
+    _collections_abc.MutableSequence.register(deque)
+
+try:
+    from _collections import defaultdict
+except ImportError:
+    pass
+
+
+################################################################################
+### OrderedDict
+################################################################################
+
+class _OrderedDictKeysView(_collections_abc.KeysView):
+
+    def __reversed__(self):
+        yield from reversed(self._mapping)
+
+class _OrderedDictItemsView(_collections_abc.ItemsView):
+
+    def __reversed__(self):
+        for key in reversed(self._mapping):
+            yield (key, self._mapping[key])
+
+class _OrderedDictValuesView(_collections_abc.ValuesView):
+
+    def __reversed__(self):
+        for key in reversed(self._mapping):
+            yield self._mapping[key]
+
+class _Link(object):
+    __slots__ = 'prev', 'next', 'key', '__weakref__'
+
+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).
+    # The sentinel is in self.__hardroot with a weakref proxy in self.__root.
+    # The prev links are weakref proxies (to prevent circular references).
+    # Individual links are kept alive by the hard reference in self.__map.
+    # Those hard references disappear when a key is deleted from an OrderedDict.
+
+    def __new__(cls, /, *args, **kwds):
+        "Create the ordered dict object and set up the underlying structures."
+        self = dict.__new__(cls)
+        self.__hardroot = _Link()
+        self.__root = root = _proxy(self.__hardroot)
+        root.prev = root.next = root
+        self.__map = {}
+        return self
+
+    def __init__(self, other=(), /, **kwds):
+        '''Initialize an ordered dictionary.  The signature is the same as
+        regular dictionaries.  Keyword argument order is preserved.
+        '''
+        self.__update(other, **kwds)
+
+    def __setitem__(self, key, value,
+                    dict_setitem=dict.__setitem__, proxy=_proxy, Link=_Link):
+        '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:
+            self.__map[key] = link = Link()
+            root = self.__root
+            last = root.prev
+            link.prev, link.next, link.key = last, root, key
+            last.next = link
+            root.prev = proxy(link)
+        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 = self.__map.pop(key)
+        link_prev = link.prev
+        link_next = link.next
+        link_prev.next = link_next
+        link_next.prev = link_prev
+        link.prev = None
+        link.next = None
+
+    def __iter__(self):
+        'od.__iter__() <==> iter(od)'
+        # Traverse the linked list in order.
+        root = self.__root
+        curr = root.next
+        while curr is not root:
+            yield curr.key
+            curr = curr.next
+
+    def __reversed__(self):
+        'od.__reversed__() <==> reversed(od)'
+        # Traverse the linked list in reverse order.
+        root = self.__root
+        curr = root.prev
+        while curr is not root:
+            yield curr.key
+            curr = curr.prev
+
+    def clear(self):
+        'od.clear() -> None.  Remove all items from od.'
+        root = self.__root
+        root.prev = root.next = root
+        self.__map.clear()
+        dict.clear(self)
+
+    def popitem(self, last=True):
+        '''Remove and return a (key, value) pair from the dictionary.
+
+        Pairs are returned in LIFO order if last is true or FIFO order if false.
+        '''
+        if not self:
+            raise KeyError('dictionary is empty')
+        root = self.__root
+        if last:
+            link = root.prev
+            link_prev = link.prev
+            link_prev.next = root
+            root.prev = link_prev
+        else:
+            link = root.next
+            link_next = link.next
+            root.next = link_next
+            link_next.prev = root
+        key = link.key
+        del self.__map[key]
+        value = dict.pop(self, key)
+        return key, value
+
+    def move_to_end(self, key, last=True):
+        '''Move an existing element to the end (or beginning if last is false).
+
+        Raise KeyError if the element does not exist.
+        '''
+        link = self.__map[key]
+        link_prev = link.prev
+        link_next = link.next
+        soft_link = link_next.prev
+        link_prev.next = link_next
+        link_next.prev = link_prev
+        root = self.__root
+        if last:
+            last = root.prev
+            link.prev = last
+            link.next = root
+            root.prev = soft_link
+            last.next = link
+        else:
+            first = root.next
+            link.prev = root
+            link.next = first
+            first.prev = soft_link
+            root.next = link
+
+    def __sizeof__(self):
+        sizeof = _sys.getsizeof
+        n = len(self) + 1                       # number of links including root
+        size = sizeof(self.__dict__)            # instance dictionary
+        size += sizeof(self.__map) * 2          # internal dict and inherited dict
+        size += sizeof(self.__hardroot) * n     # link objects
+        size += sizeof(self.__root) * n         # proxy objects
+        return size
+
+    update = __update = _collections_abc.MutableMapping.update
+
+    def keys(self):
+        "D.keys() -> a set-like object providing a view on D's keys"
+        return _OrderedDictKeysView(self)
+
+    def items(self):
+        "D.items() -> a set-like object providing a view on D's items"
+        return _OrderedDictItemsView(self)
+
+    def values(self):
+        "D.values() -> an object providing a view on D's values"
+        return _OrderedDictValuesView(self)
+
+    __ne__ = _collections_abc.MutableMapping.__ne__
+
+    __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.
+
+        '''
+        marker = self.__marker
+        result = dict.pop(self, key, marker)
+        if result is not marker:
+            # The same as in __delitem__().
+            link = self.__map.pop(key)
+            link_prev = link.prev
+            link_next = link.next
+            link_prev.next = link_next
+            link_next.prev = link_prev
+            link.prev = None
+            link.next = None
+            return result
+        if default is marker:
+            raise KeyError(key)
+        return default
+
+    def setdefault(self, key, default=None):
+        '''Insert key with a value of default if key is not in the dictionary.
+
+        Return the value for key if key is in the dictionary, else default.
+        '''
+        if key in self:
+            return self[key]
+        self[key] = default
+        return default
+
+    @_recursive_repr()
+    def __repr__(self):
+        'od.__repr__() <==> repr(od)'
+        if not self:
+            return '%s()' % (self.__class__.__name__,)
+        return '%s(%r)' % (self.__class__.__name__, list(self.items()))
+
+    def __reduce__(self):
+        'Return state information for pickling'
+        state = self.__getstate__()
+        if state:
+            if isinstance(state, tuple):
+                state, slots = state
+            else:
+                slots = {}
+            state = state.copy()
+            slots = slots.copy()
+            for k in vars(OrderedDict()):
+                state.pop(k, None)
+                slots.pop(k, None)
+            if slots:
+                state = state, slots
+            else:
+                state = state or None
+        return self.__class__, (), state, None, iter(self.items())
+
+    def copy(self):
+        'od.copy() -> a shallow copy of od'
+        return self.__class__(self)
+
+    @classmethod
+    def fromkeys(cls, iterable, value=None):
+        '''Create a new ordered dictionary with keys from iterable and values set to value.
+        '''
+        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(map(_eq, self, other))
+        return dict.__eq__(self, other)
+
+    def __ior__(self, other):
+        self.update(other)
+        return self
+
+    def __or__(self, other):
+        if not isinstance(other, dict):
+            return NotImplemented
+        new = self.__class__(self)
+        new.update(other)
+        return new
+
+    def __ror__(self, other):
+        if not isinstance(other, dict):
+            return NotImplemented
+        new = self.__class__(other)
+        new.update(self)
+        return new
+
+
+try:
+    from _collections import OrderedDict
+except ImportError:
+    # Leave the pure Python version in place.
+    pass
+
+
+################################################################################
+### namedtuple
+################################################################################
+
+try:
+    from _collections import _tuplegetter
+except ImportError:
+    _tuplegetter = lambda index, doc: property(_itemgetter(index), doc=doc)
+
+def namedtuple(typename, field_names, *, rename=False, defaults=None, module=None):
+    """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 accessible 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, str):
+        field_names = field_names.replace(',', ' ').split()
+    field_names = list(map(str, field_names))
+    typename = _sys.intern(str(typename))
+
+    if rename:
+        seen = set()
+        for index, name in enumerate(field_names):
+            if (not name.isidentifier()
+                or _iskeyword(name)
+                or name.startswith('_')
+                or name in seen):
+                field_names[index] = f'_{index}'
+            seen.add(name)
+
+    for name in [typename] + field_names:
+        if type(name) is not str:
+            raise TypeError('Type names and field names must be strings')
+        if not name.isidentifier():
+            raise ValueError('Type names and field names must be valid '
+                             f'identifiers: {name!r}')
+        if _iskeyword(name):
+            raise ValueError('Type names and field names cannot be a '
+                             f'keyword: {name!r}')
+
+    seen = set()
+    for name in field_names:
+        if name.startswith('_') and not rename:
+            raise ValueError('Field names cannot start with an underscore: '
+                             f'{name!r}')
+        if name in seen:
+            raise ValueError(f'Encountered duplicate field name: {name!r}')
+        seen.add(name)
+
+    field_defaults = {}
+    if defaults is not None:
+        defaults = tuple(defaults)
+        if len(defaults) > len(field_names):
+            raise TypeError('Got more default values than field names')
+        field_defaults = dict(reversed(list(zip(reversed(field_names),
+                                                reversed(defaults)))))
+
+    # Variables used in the methods and docstrings
+    field_names = tuple(map(_sys.intern, field_names))
+    num_fields = len(field_names)
+    arg_list = ', '.join(field_names)
+    if num_fields == 1:
+        arg_list += ','
+    repr_fmt = '(' + ', '.join(f'{name}=%r' for name in field_names) + ')'
+    tuple_new = tuple.__new__
+    _dict, _tuple, _len, _map, _zip = dict, tuple, len, map, zip
+
+    # Create all the named tuple methods to be added to the class namespace
+
+    namespace = {
+        '_tuple_new': tuple_new,
+        '__builtins__': {},
+        '__name__': f'namedtuple_{typename}',
+    }
+    code = f'lambda _cls, {arg_list}: _tuple_new(_cls, ({arg_list}))'
+    __new__ = eval(code, namespace)
+    __new__.__name__ = '__new__'
+    __new__.__doc__ = f'Create new instance of {typename}({arg_list})'
+    if defaults is not None:
+        __new__.__defaults__ = defaults
+
+    @classmethod
+    def _make(cls, iterable):
+        result = tuple_new(cls, iterable)
+        if _len(result) != num_fields:
+            raise TypeError(f'Expected {num_fields} arguments, got {len(result)}')
+        return result
+
+    _make.__func__.__doc__ = (f'Make a new {typename} object from a sequence '
+                              'or iterable')
+
+    def _replace(self, /, **kwds):
+        result = self._make(_map(kwds.pop, field_names, self))
+        if kwds:
+            raise ValueError(f'Got unexpected field names: {list(kwds)!r}')
+        return result
+
+    _replace.__doc__ = (f'Return a new {typename} object replacing specified '
+                        'fields with new values')
+
+    def __repr__(self):
+        'Return a nicely formatted representation string'
+        return self.__class__.__name__ + repr_fmt % self
+
+    def _asdict(self):
+        'Return a new dict which maps field names to their values.'
+        return _dict(_zip(self._fields, self))
+
+    def __getnewargs__(self):
+        'Return self as a plain tuple.  Used by copy and pickle.'
+        return _tuple(self)
+
+    # Modify function metadata to help with introspection and debugging
+    for method in (
+        __new__,
+        _make.__func__,
+        _replace,
+        __repr__,
+        _asdict,
+        __getnewargs__,
+    ):
+        method.__qualname__ = f'{typename}.{method.__name__}'
+
+    # Build-up the class namespace dictionary
+    # and use type() to build the result class
+    class_namespace = {
+        '__doc__': f'{typename}({arg_list})',
+        '__slots__': (),
+        '_fields': field_names,
+        '_field_defaults': field_defaults,
+        '__new__': __new__,
+        '_make': _make,
+        '_replace': _replace,
+        '__repr__': __repr__,
+        '_asdict': _asdict,
+        '__getnewargs__': __getnewargs__,
+        '__match_args__': field_names,
+    }
+    for index, name in enumerate(field_names):
+        doc = _sys.intern(f'Alias for field number {index}')
+        class_namespace[name] = _tuplegetter(index, doc)
+
+    result = type(typename, (tuple,), class_namespace)
+
+    # For pickling to work, the __module__ variable needs to be set to the frame
+    # where the named tuple is created.  Bypass this step in environments where
+    # sys._getframe is not defined (Jython for example) or sys._getframe is not
+    # defined for arguments greater than 0 (IronPython), or where the user has
+    # specified a particular module.
+    if module is None:
+        try:
+            module = _sys._getframe(1).f_globals.get('__name__', '__main__')
+        except (AttributeError, ValueError):
+            pass
+    if module is not None:
+        result.__module__ = module
+
+    return result
+
+
+########################################################################
+###  Counter
+########################################################################
+
+def _count_elements(mapping, iterable):
+    'Tally elements from the iterable.'
+    mapping_get = mapping.get
+    for elem in iterable:
+        mapping[elem] = mapping_get(elem, 0) + 1
+
+try:                                    # Load C helper function if available
+    from _collections import _count_elements
+except ImportError:
+    pass
+
+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().__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 total(self):
+        'Sum of the counts'
+        return sum(self.values())
+
+    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('abracadabra').most_common(3)
+        [('a', 5), ('b', 2), ('r', 2)]
+
+        '''
+        # Emulate Bag.sortedByCount from Smalltalk
+        if n is None:
+            return sorted(self.items(), key=_itemgetter(1), reverse=True)
+
+        # Lazy import to speedup Python startup time
+        import heapq
+        return heapq.nlargest(n, self.items(), 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
+        >>> import math
+        >>> prime_factors = Counter({2: 2, 3: 3, 17: 1})
+        >>> math.prod(prime_factors.elements())
+        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.items()))
+
+    # Override dict methods where necessary
+
+    @classmethod
+    def fromkeys(cls, iterable, v=None):
+        # There is no equivalent method for counters because the semantics
+        # would be ambiguous in cases such as Counter.fromkeys('aaabbc', v=2).
+        # Initializing counters to zero values isn't necessary because zero
+        # is already the default value for counter lookups.  Initializing
+        # to one is easily accomplished with Counter(set(iterable)).  For
+        # more exotic cases, create a dictionary first using a dictionary
+        # comprehension or dict.fromkeys().
+        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, _collections_abc.Mapping):
+                if self:
+                    self_get = self.get
+                    for elem, count in iterable.items():
+                        self[elem] = count + self_get(elem, 0)
+                else:
+                    # fast path when counter is empty
+                    super().update(iterable)
+            else:
+                _count_elements(self, iterable)
+        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, _collections_abc.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().__delitem__(elem)
+
+    def __repr__(self):
+        if not self:
+            return f'{self.__class__.__name__}()'
+        try:
+            # dict() preserves the ordering returned by most_common()
+            d = dict(self.most_common())
+        except TypeError:
+            # handle case where values are not orderable
+            d = dict(self)
+        return f'{self.__class__.__name__}({d!r})'
+
+    # 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()
+    #
+    # Results are ordered according to when an element is first
+    # encountered in the left operand and then by the order
+    # encountered in the right operand.
+    #
+    # When the multiplicities are all zero or one, multiset operations
+    # are guaranteed to be equivalent to the corresponding operations
+    # for regular sets.
+    #     Given counter multisets such as:
+    #         cp = Counter(a=1, b=0, c=1)
+    #         cq = Counter(c=1, d=0, e=1)
+    #     The corresponding regular sets would be:
+    #         sp = {'a', 'c'}
+    #         sq = {'c', 'e'}
+    #     All of the following relations would hold:
+    #         set(cp + cq) == sp | sq
+    #         set(cp - cq) == sp - sq
+    #         set(cp | cq) == sp | sq
+    #         set(cp & cq) == sp & sq
+    #         (cp == cq) == (sp == sq)
+    #         (cp != cq) == (sp != sq)
+    #         (cp <= cq) == (sp <= sq)
+    #         (cp < cq) == (sp < sq)
+    #         (cp >= cq) == (sp >= sq)
+    #         (cp > cq) == (sp > sq)
+
+    def __eq__(self, other):
+        'True if all counts agree. Missing counts are treated as zero.'
+        if not isinstance(other, Counter):
+            return NotImplemented
+        return all(self[e] == other[e] for c in (self, other) for e in c)
+
+    def __ne__(self, other):
+        'True if any counts disagree. Missing counts are treated as zero.'
+        if not isinstance(other, Counter):
+            return NotImplemented
+        return not self == other
+
+    def __le__(self, other):
+        'True if all counts in self are a subset of those in other.'
+        if not isinstance(other, Counter):
+            return NotImplemented
+        return all(self[e] <= other[e] for c in (self, other) for e in c)
+
+    def __lt__(self, other):
+        'True if all counts in self are a proper subset of those in other.'
+        if not isinstance(other, Counter):
+            return NotImplemented
+        return self <= other and self != other
+
+    def __ge__(self, other):
+        'True if all counts in self are a superset of those in other.'
+        if not isinstance(other, Counter):
+            return NotImplemented
+        return all(self[e] >= other[e] for c in (self, other) for e in c)
+
+    def __gt__(self, other):
+        'True if all counts in self are a proper superset of those in other.'
+        if not isinstance(other, Counter):
+            return NotImplemented
+        return self >= other and self != other
+
+    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
+
+    def __pos__(self):
+        'Adds an empty counter, effectively stripping negative and zero counts'
+        result = Counter()
+        for elem, count in self.items():
+            if count > 0:
+                result[elem] = count
+        return result
+
+    def __neg__(self):
+        '''Subtracts from an empty counter.  Strips positive and zero counts,
+        and flips the sign on negative counts.
+
+        '''
+        result = Counter()
+        for elem, count in self.items():
+            if count < 0:
+                result[elem] = 0 - count
+        return result
+
+    def _keep_positive(self):
+        '''Internal method to strip elements with a negative or zero count'''
+        nonpositive = [elem for elem, count in self.items() if not count > 0]
+        for elem in nonpositive:
+            del self[elem]
+        return self
+
+    def __iadd__(self, other):
+        '''Inplace add from another counter, keeping only positive counts.
+
+        >>> c = Counter('abbb')
+        >>> c += Counter('bcc')
+        >>> c
+        Counter({'b': 4, 'c': 2, 'a': 1})
+
+        '''
+        for elem, count in other.items():
+            self[elem] += count
+        return self._keep_positive()
+
+    def __isub__(self, other):
+        '''Inplace subtract counter, but keep only results with positive counts.
+
+        >>> c = Counter('abbbc')
+        >>> c -= Counter('bccd')
+        >>> c
+        Counter({'b': 2, 'a': 1})
+
+        '''
+        for elem, count in other.items():
+            self[elem] -= count
+        return self._keep_positive()
+
+    def __ior__(self, other):
+        '''Inplace union is the maximum of value from either counter.
+
+        >>> c = Counter('abbb')
+        >>> c |= Counter('bcc')
+        >>> c
+        Counter({'b': 3, 'c': 2, 'a': 1})
+
+        '''
+        for elem, other_count in other.items():
+            count = self[elem]
+            if other_count > count:
+                self[elem] = other_count
+        return self._keep_positive()
+
+    def __iand__(self, other):
+        '''Inplace intersection is the minimum of corresponding counts.
+
+        >>> c = Counter('abbb')
+        >>> c &= Counter('bcc')
+        >>> c
+        Counter({'b': 1})
+
+        '''
+        for elem, count in self.items():
+            other_count = other[elem]
+            if other_count < count:
+                self[elem] = other_count
+        return self._keep_positive()
+
+
+########################################################################
+###  ChainMap
+########################################################################
+
+class ChainMap(_collections_abc.MutableMapping):
+    ''' A ChainMap groups multiple dicts (or other mappings) together
+    to create a single, updateable view.
+
+    The underlying mappings are stored in a list.  That list is public and can
+    be accessed or updated using the *maps* attribute.  There is no other
+    state.
+
+    Lookups search the underlying mappings successively until a key is found.
+    In contrast, writes, updates, and deletions only operate on the first
+    mapping.
+
+    '''
+
+    def __init__(self, *maps):
+        '''Initialize a ChainMap by setting *maps* to the given mappings.
+        If no mappings are provided, a single empty dictionary is used.
+
+        '''
+        self.maps = list(maps) or [{}]          # always at least one map
+
+    def __missing__(self, key):
+        raise KeyError(key)
+
+    def __getitem__(self, key):
+        for mapping in self.maps:
+            try:
+                return mapping[key]             # can't use 'key in mapping' with defaultdict
+            except KeyError:
+                pass
+        return self.__missing__(key)            # support subclasses that define __missing__
+
+    def get(self, key, default=None):
+        return self[key] if key in self else default
+
+    def __len__(self):
+        return len(set().union(*self.maps))     # reuses stored hash values if possible
+
+    def __iter__(self):
+        d = {}
+        for mapping in reversed(self.maps):
+            d.update(dict.fromkeys(mapping))    # reuses stored hash values if possible
+        return iter(d)
+
+    def __contains__(self, key):
+        return any(key in m for m in self.maps)
+
+    def __bool__(self):
+        return any(self.maps)
+
+    @_recursive_repr()
+    def __repr__(self):
+        return f'{self.__class__.__name__}({", ".join(map(repr, self.maps))})'
+
+    @classmethod
+    def fromkeys(cls, iterable, *args):
+        'Create a ChainMap with a single dict created from the iterable.'
+        return cls(dict.fromkeys(iterable, *args))
+
+    def copy(self):
+        'New ChainMap or subclass with a new copy of maps[0] and refs to maps[1:]'
+        return self.__class__(self.maps[0].copy(), *self.maps[1:])
+
+    __copy__ = copy
+
+    def new_child(self, m=None, **kwargs):      # like Django's Context.push()
+        '''New ChainMap with a new map followed by all previous maps.
+        If no map is provided, an empty dict is used.
+        Keyword arguments update the map or new empty dict.
+        '''
+        if m is None:
+            m = kwargs
+        elif kwargs:
+            m.update(kwargs)
+        return self.__class__(m, *self.maps)
+
+    @property
+    def parents(self):                          # like Django's Context.pop()
+        'New ChainMap from maps[1:].'
+        return self.__class__(*self.maps[1:])
+
+    def __setitem__(self, key, value):
+        self.maps[0][key] = value
+
+    def __delitem__(self, key):
+        try:
+            del self.maps[0][key]
+        except KeyError:
+            raise KeyError(f'Key not found in the first mapping: {key!r}')
+
+    def popitem(self):
+        'Remove and return an item pair from maps[0]. Raise KeyError is maps[0] is empty.'
+        try:
+            return self.maps[0].popitem()
+        except KeyError:
+            raise KeyError('No keys found in the first mapping.')
+
+    def pop(self, key, *args):
+        'Remove *key* from maps[0] and return its value. Raise KeyError if *key* not in maps[0].'
+        try:
+            return self.maps[0].pop(key, *args)
+        except KeyError:
+            raise KeyError(f'Key not found in the first mapping: {key!r}')
+
+    def clear(self):
+        'Clear maps[0], leaving maps[1:] intact.'
+        self.maps[0].clear()
+
+    def __ior__(self, other):
+        self.maps[0].update(other)
+        return self
+
+    def __or__(self, other):
+        if not isinstance(other, _collections_abc.Mapping):
+            return NotImplemented
+        m = self.copy()
+        m.maps[0].update(other)
+        return m
+
+    def __ror__(self, other):
+        if not isinstance(other, _collections_abc.Mapping):
+            return NotImplemented
+        m = dict(other)
+        for child in reversed(self.maps):
+            m.update(child)
+        return self.__class__(m)
+
+
+################################################################################
+### UserDict
+################################################################################
+
+class UserDict(_collections_abc.MutableMapping):
+
+    # Start by filling-out the abstract methods
+    def __init__(self, dict=None, /, **kwargs):
+        self.data = {}
+        if dict is not None:
+            self.update(dict)
+        if kwargs:
+            self.update(kwargs)
+
+    def __len__(self):
+        return len(self.data)
+
+    def __getitem__(self, key):
+        if key in self.data:
+            return self.data[key]
+        if hasattr(self.__class__, "__missing__"):
+            return self.__class__.__missing__(self, key)
+        raise KeyError(key)
+
+    def __setitem__(self, key, item):
+        self.data[key] = item
+
+    def __delitem__(self, key):
+        del self.data[key]
+
+    def __iter__(self):
+        return iter(self.data)
+
+    # Modify __contains__ to work correctly when __missing__ is present
+    def __contains__(self, key):
+        return key in self.data
+
+    # Now, add the methods in dicts but not in MutableMapping
+    def __repr__(self):
+        return repr(self.data)
+
+    def __or__(self, other):
+        if isinstance(other, UserDict):
+            return self.__class__(self.data | other.data)
+        if isinstance(other, dict):
+            return self.__class__(self.data | other)
+        return NotImplemented
+
+    def __ror__(self, other):
+        if isinstance(other, UserDict):
+            return self.__class__(other.data | self.data)
+        if isinstance(other, dict):
+            return self.__class__(other | self.data)
+        return NotImplemented
+
+    def __ior__(self, other):
+        if isinstance(other, UserDict):
+            self.data |= other.data
+        else:
+            self.data |= other
+        return self
+
+    def __copy__(self):
+        inst = self.__class__.__new__(self.__class__)
+        inst.__dict__.update(self.__dict__)
+        # Create a copy and avoid triggering descriptors
+        inst.__dict__["data"] = self.__dict__["data"].copy()
+        return inst
+
+    def copy(self):
+        if self.__class__ is UserDict:
+            return UserDict(self.data.copy())
+        import copy
+        data = self.data
+        try:
+            self.data = {}
+            c = copy.copy(self)
+        finally:
+            self.data = data
+        c.update(self)
+        return c
+
+    @classmethod
+    def fromkeys(cls, iterable, value=None):
+        d = cls()
+        for key in iterable:
+            d[key] = value
+        return d
+
+
+################################################################################
+### UserList
+################################################################################
+
+class UserList(_collections_abc.MutableSequence):
+    """A more or less complete user-defined wrapper around list objects."""
+
+    def __init__(self, initlist=None):
+        self.data = []
+        if initlist is not None:
+            # XXX should this accept an arbitrary sequence?
+            if type(initlist) == type(self.data):
+                self.data[:] = initlist
+            elif isinstance(initlist, UserList):
+                self.data[:] = initlist.data[:]
+            else:
+                self.data = list(initlist)
+
+    def __repr__(self):
+        return repr(self.data)
+
+    def __lt__(self, other):
+        return self.data < self.__cast(other)
+
+    def __le__(self, other):
+        return self.data <= self.__cast(other)
+
+    def __eq__(self, other):
+        return self.data == self.__cast(other)
+
+    def __gt__(self, other):
+        return self.data > self.__cast(other)
+
+    def __ge__(self, other):
+        return self.data >= self.__cast(other)
+
+    def __cast(self, other):
+        return other.data if isinstance(other, UserList) else other
+
+    def __contains__(self, item):
+        return item in self.data
+
+    def __len__(self):
+        return len(self.data)
+
+    def __getitem__(self, i):
+        if isinstance(i, slice):
+            return self.__class__(self.data[i])
+        else:
+            return self.data[i]
+
+    def __setitem__(self, i, item):
+        self.data[i] = item
+
+    def __delitem__(self, i):
+        del self.data[i]
+
+    def __add__(self, other):
+        if isinstance(other, UserList):
+            return self.__class__(self.data + other.data)
+        elif isinstance(other, type(self.data)):
+            return self.__class__(self.data + other)
+        return self.__class__(self.data + list(other))
+
+    def __radd__(self, other):
+        if isinstance(other, UserList):
+            return self.__class__(other.data + self.data)
+        elif isinstance(other, type(self.data)):
+            return self.__class__(other + self.data)
+        return self.__class__(list(other) + self.data)
+
+    def __iadd__(self, other):
+        if isinstance(other, UserList):
+            self.data += other.data
+        elif isinstance(other, type(self.data)):
+            self.data += other
+        else:
+            self.data += list(other)
+        return self
+
+    def __mul__(self, n):
+        return self.__class__(self.data * n)
+
+    __rmul__ = __mul__
+
+    def __imul__(self, n):
+        self.data *= n
+        return self
+
+    def __copy__(self):
+        inst = self.__class__.__new__(self.__class__)
+        inst.__dict__.update(self.__dict__)
+        # Create a copy and avoid triggering descriptors
+        inst.__dict__["data"] = self.__dict__["data"][:]
+        return inst
+
+    def append(self, item):
+        self.data.append(item)
+
+    def insert(self, i, item):
+        self.data.insert(i, item)
+
+    def pop(self, i=-1):
+        return self.data.pop(i)
+
+    def remove(self, item):
+        self.data.remove(item)
+
+    def clear(self):
+        self.data.clear()
+
+    def copy(self):
+        return self.__class__(self)
+
+    def count(self, item):
+        return self.data.count(item)
+
+    def index(self, item, *args):
+        return self.data.index(item, *args)
+
+    def reverse(self):
+        self.data.reverse()
+
+    def sort(self, /, *args, **kwds):
+        self.data.sort(*args, **kwds)
+
+    def extend(self, other):
+        if isinstance(other, UserList):
+            self.data.extend(other.data)
+        else:
+            self.data.extend(other)
+
+
+################################################################################
+### UserString
+################################################################################
+
+class UserString(_collections_abc.Sequence):
+
+    def __init__(self, seq):
+        if isinstance(seq, str):
+            self.data = seq
+        elif isinstance(seq, UserString):
+            self.data = seq.data[:]
+        else:
+            self.data = str(seq)
+
+    def __str__(self):
+        return str(self.data)
+
+    def __repr__(self):
+        return repr(self.data)
+
+    def __int__(self):
+        return int(self.data)
+
+    def __float__(self):
+        return float(self.data)
+
+    def __complex__(self):
+        return complex(self.data)
+
+    def __hash__(self):
+        return hash(self.data)
+
+    def __getnewargs__(self):
+        return (self.data[:],)
+
+    def __eq__(self, string):
+        if isinstance(string, UserString):
+            return self.data == string.data
+        return self.data == string
+
+    def __lt__(self, string):
+        if isinstance(string, UserString):
+            return self.data < string.data
+        return self.data < string
+
+    def __le__(self, string):
+        if isinstance(string, UserString):
+            return self.data <= string.data
+        return self.data <= string
+
+    def __gt__(self, string):
+        if isinstance(string, UserString):
+            return self.data > string.data
+        return self.data > string
+
+    def __ge__(self, string):
+        if isinstance(string, UserString):
+            return self.data >= string.data
+        return self.data >= string
+
+    def __contains__(self, char):
+        if isinstance(char, UserString):
+            char = char.data
+        return char in self.data
+
+    def __len__(self):
+        return len(self.data)
+
+    def __getitem__(self, index):
+        return self.__class__(self.data[index])
+
+    def __add__(self, other):
+        if isinstance(other, UserString):
+            return self.__class__(self.data + other.data)
+        elif isinstance(other, str):
+            return self.__class__(self.data + other)
+        return self.__class__(self.data + str(other))
+
+    def __radd__(self, other):
+        if isinstance(other, str):
+            return self.__class__(other + self.data)
+        return self.__class__(str(other) + self.data)
+
+    def __mul__(self, n):
+        return self.__class__(self.data * n)
+
+    __rmul__ = __mul__
+
+    def __mod__(self, args):
+        return self.__class__(self.data % args)
+
+    def __rmod__(self, template):
+        return self.__class__(str(template) % self)
+
+    # the following methods are defined in alphabetical order:
+    def capitalize(self):
+        return self.__class__(self.data.capitalize())
+
+    def casefold(self):
+        return self.__class__(self.data.casefold())
+
+    def center(self, width, *args):
+        return self.__class__(self.data.center(width, *args))
+
+    def count(self, sub, start=0, end=_sys.maxsize):
+        if isinstance(sub, UserString):
+            sub = sub.data
+        return self.data.count(sub, start, end)
+
+    def removeprefix(self, prefix, /):
+        if isinstance(prefix, UserString):
+            prefix = prefix.data
+        return self.__class__(self.data.removeprefix(prefix))
+
+    def removesuffix(self, suffix, /):
+        if isinstance(suffix, UserString):
+            suffix = suffix.data
+        return self.__class__(self.data.removesuffix(suffix))
+
+    def encode(self, encoding='utf-8', errors='strict'):
+        encoding = 'utf-8' if encoding is None else encoding
+        errors = 'strict' if errors is None else errors
+        return self.data.encode(encoding, errors)
+
+    def endswith(self, suffix, start=0, end=_sys.maxsize):
+        return self.data.endswith(suffix, start, end)
+
+    def expandtabs(self, tabsize=8):
+        return self.__class__(self.data.expandtabs(tabsize))
+
+    def find(self, sub, start=0, end=_sys.maxsize):
+        if isinstance(sub, UserString):
+            sub = sub.data
+        return self.data.find(sub, start, end)
+
+    def format(self, /, *args, **kwds):
+        return self.data.format(*args, **kwds)
+
+    def format_map(self, mapping):
+        return self.data.format_map(mapping)
+
+    def index(self, sub, start=0, end=_sys.maxsize):
+        return self.data.index(sub, start, end)
+
+    def isalpha(self):
+        return self.data.isalpha()
+
+    def isalnum(self):
+        return self.data.isalnum()
+
+    def isascii(self):
+        return self.data.isascii()
+
+    def isdecimal(self):
+        return self.data.isdecimal()
+
+    def isdigit(self):
+        return self.data.isdigit()
+
+    def isidentifier(self):
+        return self.data.isidentifier()
+
+    def islower(self):
+        return self.data.islower()
+
+    def isnumeric(self):
+        return self.data.isnumeric()
+
+    def isprintable(self):
+        return self.data.isprintable()
+
+    def isspace(self):
+        return self.data.isspace()
+
+    def istitle(self):
+        return self.data.istitle()
+
+    def isupper(self):
+        return self.data.isupper()
+
+    def join(self, seq):
+        return self.data.join(seq)
+
+    def ljust(self, width, *args):
+        return self.__class__(self.data.ljust(width, *args))
+
+    def lower(self):
+        return self.__class__(self.data.lower())
+
+    def lstrip(self, chars=None):
+        return self.__class__(self.data.lstrip(chars))
+
+    maketrans = str.maketrans
+
+    def partition(self, sep):
+        return self.data.partition(sep)
+
+    def replace(self, old, new, maxsplit=-1):
+        if isinstance(old, UserString):
+            old = old.data
+        if isinstance(new, UserString):
+            new = new.data
+        return self.__class__(self.data.replace(old, new, maxsplit))
+
+    def rfind(self, sub, start=0, end=_sys.maxsize):
+        if isinstance(sub, UserString):
+            sub = sub.data
+        return self.data.rfind(sub, start, end)
+
+    def rindex(self, sub, start=0, end=_sys.maxsize):
+        return self.data.rindex(sub, start, end)
+
+    def rjust(self, width, *args):
+        return self.__class__(self.data.rjust(width, *args))
+
+    def rpartition(self, sep):
+        return self.data.rpartition(sep)
+
+    def rstrip(self, chars=None):
+        return self.__class__(self.data.rstrip(chars))
+
+    def split(self, sep=None, maxsplit=-1):
+        return self.data.split(sep, maxsplit)
+
+    def rsplit(self, sep=None, maxsplit=-1):
+        return self.data.rsplit(sep, maxsplit)
+
+    def splitlines(self, keepends=False):
+        return self.data.splitlines(keepends)
+
+    def startswith(self, prefix, start=0, end=_sys.maxsize):
+        return self.data.startswith(prefix, start, end)
+
+    def strip(self, chars=None):
+        return self.__class__(self.data.strip(chars))
+
+    def swapcase(self):
+        return self.__class__(self.data.swapcase())
+
+    def title(self):
+        return self.__class__(self.data.title())
+
+    def translate(self, *args):
+        return self.__class__(self.data.translate(*args))
+
+    def upper(self):
+        return self.__class__(self.data.upper())
+
+    def zfill(self, width):
+        return self.__class__(self.data.zfill(width))
diff --git a/contrib/tools/python3/src/Lib/collections/abc.py b/contrib/tools/python3/src/Lib/collections/abc.py
new file mode 100644
index 0000000000..86ca8b8a84
--- /dev/null
+++ b/contrib/tools/python3/src/Lib/collections/abc.py
@@ -0,0 +1,3 @@
+from _collections_abc import *
+from _collections_abc import __all__
+from _collections_abc import _CallableGenericAlias