# odict.py
# An Ordered Dictionary object
# Copyright (C) 2005 Nicola Larosa, Michael Foord
# E-mail: nico-NoSp@m-tekNico.net, fuzzyman AT voidspace DOT org DOT uk

# This software is licensed under the terms of the BSD license.
# http://www.voidspace.org.uk/python/license.shtml
# Basically you're free to copy, modify, distribute and relicense it,
# So long as you keep a copy of the license with it.

# Scripts maintained at http://www.voidspace.org.uk/python/index.shtml
# For information about bugfixes, updates and support, please join the
# Pythonutils mailing list:
# http://groups.google.com/group/pythonutils/
# Comments, suggestions and bug reports welcome.

"""A dict that keeps keys in insertion order"""

__author__ = ('Nicola Larosa <nico-NoSp@m-tekNico.net>,'
    'Michael Foord <fuzzyman AT voidspace DOT org DOT uk>')

__docformat__ = "restructuredtext en"

__revision__ = '$Id: odict.py 129 2005-09-12 18:15:28Z teknico $'

__version__ = '0.2.1'

__all__ = ['OrderedDict', 'SequenceOrderedDict']

#from __future__ import generators
from warnings import warn
from types import SliceType

import sys
INTP_VER = sys.version_info[:2]
if INTP_VER < (2, 2):
    raise RuntimeError("Python v.2.2 or later needed")

class OrderedDict(dict):
    """
    A class of dictionary that keeps the insertion order of keys.
    
    All appropriate methods return keys, items, or values in an ordered way.
    
    All normal dictionary methods are available. Update and comparison is
    restricted to other OrderedDict objects.
    
    Various sequence methods are available, including the ability to explicitly
    mutate the key ordering.
    
    __contains__ tests:
    
    >>> d = OrderedDict(((1, 3),))
    >>> 1 in d
    1
    >>> 4 in d
    0
    
    __getitem__ tests:
    
    >>> OrderedDict(((1, 3), (3, 2), (2, 1)))[2]
    1
    >>> OrderedDict(((1, 3), (3, 2), (2, 1)))[4]
    Traceback (most recent call last):
    KeyError: 4
    
    __len__ tests:
    
    >>> len(OrderedDict())
    0
    >>> len(OrderedDict(((1, 3), (3, 2), (2, 1))))
    3
    
    get tests:
    
    >>> d = OrderedDict(((1, 3), (3, 2), (2, 1)))
    >>> d.get(1)
    3
    >>> d.get(4) is None
    1
    >>> d.get(4, 5)
    5
    >>> d
    OrderedDict([(1, 3), (3, 2), (2, 1)])
    
    has_key tests:
    
    >>> d = OrderedDict(((1, 3), (3, 2), (2, 1)))
    >>> d.has_key(1)
    1
    >>> d.has_key(4)
    0
    """

    def __init__(self, init_val=(), strict=False):
        """
        Create a new ordered dictionary. Cannot init from a normal dict,
        nor from kwargs, since items order is undefined in those cases.
        
        If the ``strict`` keyword argument is ``True`` (``False`` is the
        default) then when doing slice assignment - the ``OrderedDict`` you are
        assigning from *must not* contain any keys in the remaining dict.
        
        >>> OrderedDict()
        OrderedDict([])
        >>> OrderedDict({1: 1})
        Traceback (most recent call last):
        TypeError: undefined order, cannot get items from dict
        >>> d = OrderedDict(((1, 3), (3, 2), (2, 1)))
        >>> d
        OrderedDict([(1, 3), (3, 2), (2, 1)])
        >>> OrderedDict(d)
        OrderedDict([(1, 3), (3, 2), (2, 1)])
        """
        self.strict = strict
        dict.__init__(self)
        if isinstance(init_val, OrderedDict):
            self._sequence = init_val.keys()
            dict.update(self, init_val)
        elif isinstance(init_val, dict):
            # we lose compatibility with other ordered dict types this way
            raise TypeError('undefined order, cannot get items from dict')
        else:
            self._sequence = []
            # FIXME: efficiency ?
            # NOTE: Can't just do ``dict.__update__`` since duplicate items
            #   would be chosen in an arbitrary order, we need to guarantee
            #   that the last one is used.
            idx = 0
            # sequence of 2-item sequences, or error
            for item in init_val:
                try:
                    key, val = item
                except TypeError:
                    raise TypeError('cannot convert dictionary update'
                        ' sequence element #%d to a sequence' % idx)
                self[key] = val
                idx += 1

### Special methods ###

    def __delitem__(self, key):
        """
        >>> d = OrderedDict(((1, 3), (3, 2), (2, 1)))
        >>> del d[3]
        >>> d
        OrderedDict([(1, 3), (2, 1)])
        >>> del d[3]
        Traceback (most recent call last):
        KeyError: 3
        >>> d[3] = 2
        >>> d
        OrderedDict([(1, 3), (2, 1), (3, 2)])
        >>> del d[0:1]
        >>> d
        OrderedDict([(2, 1), (3, 2)])
        """
        if isinstance(key, SliceType):
            # FIXME: efficiency ?
            keys = self._sequence[key]
            for entry in keys:
                dict.__delitem__(self, entry)
            del self._sequence[key]
        else:
            # do the dict.__delitem__ *first* as it raises
            # the more appropriate error
            dict.__delitem__(self, key)
            self._sequence.remove(key)

    def __eq__(self, other):
        """
        >>> d = OrderedDict(((1, 3), (3, 2), (2, 1)))
        >>> d == OrderedDict(d)
        1
        >>> d == OrderedDict(((1, 3), (2, 1), (3, 2)))
        0
        >>> d == OrderedDict(((1, 0), (3, 2), (2, 1)))
        0
        >>> d == OrderedDict(((0, 3), (3, 2), (2, 1)))
        0
        >>> d == dict(d)
        Traceback (most recent call last):
        TypeError: Equality undefined for OrderedDicts and dictionaries
        >>> d == False
        0
        """
        if isinstance(other, dict):
            if not isinstance(other, OrderedDict):
                raise TypeError('Equality undefined for OrderedDicts and '
                    'dictionaries')
            # FIXME: efficiency ?
            #   Generate both item lists for each compare
            return (self.items() == other.items())
        else:
            return False

    def __lt__(self, other):
        """
        >>> d = OrderedDict(((1, 3), (3, 2), (2, 1)))
        >>> c = OrderedDict(((0, 3), (3, 2), (2, 1)))
        >>> c < d
        1
        >>> d < c
        0
        >>> d < dict(c)
        Traceback (most recent call last):
        TypeError: Can only compare with other OrderedDicts
        """
        if not isinstance(other, OrderedDict):
            raise TypeError('Can only compare with other OrderedDicts')
        # FIXME: efficiency ?
        #   Generate both item lists for each compare
        return (self.items() < other.items())

    def __le__(self, other):
        """
        >>> d = OrderedDict(((1, 3), (3, 2), (2, 1)))
        >>> c = OrderedDict(((0, 3), (3, 2), (2, 1)))
        >>> e = OrderedDict(d)
        >>> c <= d
        1
        >>> d <= c
        0
        >>> d <= dict(c)
        Traceback (most recent call last):
        TypeError: Can only compare with other OrderedDicts
        >>> d <= e
        1
        """
        if not isinstance(other, OrderedDict):
            raise TypeError('Can only compare with other OrderedDicts')
        # FIXME: efficiency ?
        #   Generate both item lists for each compare
        return (self.items() <= other.items())

    def __ne__(self, other):
        """
        >>> d = OrderedDict(((1, 3), (3, 2), (2, 1)))
        >>> d != OrderedDict(d)
        0
        >>> d != OrderedDict(((1, 3), (2, 1), (3, 2)))
        1
        >>> d != OrderedDict(((1, 0), (3, 2), (2, 1)))
        1
        >>> d == OrderedDict(((0, 3), (3, 2), (2, 1)))
        0
        >>> d != dict(d)
        Traceback (most recent call last):
        TypeError: Inequality undefined for OrderedDicts and dictionaries
        >>> d != False
        1
        """
        if isinstance(other, dict):
            if not isinstance(other, OrderedDict):
                raise TypeError('Inequality undefined for OrderedDicts and '
                    'dictionaries')
            # FIXME: efficiency ?
            #   Generate both item lists for each compare
            return not (self.items() == other.items())
        else:
            return True

    def __gt__(self, other):
        """
        >>> d = OrderedDict(((1, 3), (3, 2), (2, 1)))
        >>> c = OrderedDict(((0, 3), (3, 2), (2, 1)))
        >>> d > c
        1
        >>> c > d
        0
        >>> d > dict(c)
        Traceback (most recent call last):
        TypeError: Can only compare with other OrderedDicts
        """
        if not isinstance(other, OrderedDict):
            raise TypeError('Can only compare with other OrderedDicts')
        # FIXME: efficiency ?
        #   Generate both item lists for each compare
        return (self.items() > other.items())

    def __ge__(self, other):
        """
        >>> d = OrderedDict(((1, 3), (3, 2), (2, 1)))
        >>> c = OrderedDict(((0, 3), (3, 2), (2, 1)))
        >>> e = OrderedDict(d)
        >>> c >= d
        0
        >>> d >= c
        1
        >>> d >= dict(c)
        Traceback (most recent call last):
        TypeError: Can only compare with other OrderedDicts
        >>> e >= d
        1
        """
        if not isinstance(other, OrderedDict):
            raise TypeError('Can only compare with other OrderedDicts')
        # FIXME: efficiency ?
        #   Generate both item lists for each compare
        return (self.items() >= other.items())

    def __repr__(self):
        """
        Used for __repr__ and __str__
        
        >>> r1 = repr(OrderedDict((('a', 'b'), ('c', 'd'), ('e', 'f'))))
        >>> r1
        "OrderedDict([('a', 'b'), ('c', 'd'), ('e', 'f')])"
        >>> r2 = repr(OrderedDict((('a', 'b'), ('e', 'f'), ('c', 'd'))))
        >>> r2
        "OrderedDict([('a', 'b'), ('e', 'f'), ('c', 'd')])"
        >>> r1 == str(OrderedDict((('a', 'b'), ('c', 'd'), ('e', 'f'))))
        1
        >>> r2 == str(OrderedDict((('a', 'b'), ('e', 'f'), ('c', 'd'))))
        1
        """
        return '%s([%s])' % (self.__class__.__name__, ', '.join(
            ['(%r, %r)' % (key, self[key]) for key in self._sequence]))

    def __setitem__(self, key, val):
        """
        Allows slice assignment, so long as the slice is an OrderedDict
        >>> d = OrderedDict()
        >>> d['a'] = 'b'
        >>> d['b'] = 'a'
        >>> d[3] = 12
        >>> d
        OrderedDict([('a', 'b'), ('b', 'a'), (3, 12)])
        >>> d[:] = OrderedDict(((1, 2), (2, 3), (3, 4)))
        >>> d
        OrderedDict([(1, 2), (2, 3), (3, 4)])
        >>> d[::2] = OrderedDict(((7, 8), (9, 10)))
        >>> d
        OrderedDict([(7, 8), (2, 3), (9, 10)])
        >>> d = OrderedDict(((0, 1), (1, 2), (2, 3), (3, 4)))
        >>> d[1:3] = OrderedDict(((1, 2), (5, 6), (7, 8)))
        >>> d
        OrderedDict([(0, 1), (1, 2), (5, 6), (7, 8), (3, 4)])
        >>> d = OrderedDict(((0, 1), (1, 2), (2, 3), (3, 4)), strict=True)
        >>> d[1:3] = OrderedDict(((1, 2), (5, 6), (7, 8)))
        >>> d
        OrderedDict([(0, 1), (1, 2), (5, 6), (7, 8), (3, 4)])
        
        >>> a = OrderedDict(((0, 1), (1, 2), (2, 3)), strict=True)
        >>> a[3] = 4
        >>> a
        OrderedDict([(0, 1), (1, 2), (2, 3), (3, 4)])
        >>> a[::1] = OrderedDict([(0, 1), (1, 2), (2, 3), (3, 4)])
        >>> a
        OrderedDict([(0, 1), (1, 2), (2, 3), (3, 4)])
        >>> a[:2] = OrderedDict([(0, 1), (1, 2), (2, 3), (3, 4), (4, 5)])
        Traceback (most recent call last):
        ValueError: slice assignment must be from unique keys
        >>> a = OrderedDict(((0, 1), (1, 2), (2, 3)))
        >>> a[3] = 4
        >>> a
        OrderedDict([(0, 1), (1, 2), (2, 3), (3, 4)])
        >>> a[::1] = OrderedDict([(0, 1), (1, 2), (2, 3), (3, 4)])
        >>> a
        OrderedDict([(0, 1), (1, 2), (2, 3), (3, 4)])
        >>> a[:2] = OrderedDict([(0, 1), (1, 2), (2, 3), (3, 4)])
        >>> a
        OrderedDict([(0, 1), (1, 2), (2, 3), (3, 4)])
        >>> a[::-1] = OrderedDict([(0, 1), (1, 2), (2, 3), (3, 4)])
        >>> a
        OrderedDict([(3, 4), (2, 3), (1, 2), (0, 1)])
        
        >>> d = OrderedDict([(0, 1), (1, 2), (2, 3), (3, 4)])
        >>> d[:1] = 3
        Traceback (most recent call last):
        TypeError: slice assignment requires an OrderedDict
        
        >>> d = OrderedDict([(0, 1), (1, 2), (2, 3), (3, 4)])
        >>> d[:1] = OrderedDict([(9, 8)])
        >>> d
        OrderedDict([(9, 8), (1, 2), (2, 3), (3, 4)])
        """
        if isinstance(key, SliceType):
            if not isinstance(val, OrderedDict):
                # FIXME: allow a list of tuples ?
                raise TypeError('slice assignment requires an OrderedDict')
            keys = self._sequence[key]
            indexes = range(len(self._sequence))[key]
            if key.step is None:
                # NOTE: new slice may not be the same size as the one being
                #   overwritten !
                # NOTE: What is the algorithm for an impossible slice ?
                #   e.g. d[5:3]
                pos = key.start or 0
                del self[key]
                newkeys = val.keys()
                for k in newkeys:
                    if k in self:
                        if self.strict:
                            raise ValueError('slice assignment must be from '
                                'unique keys')
                        else:
                            # NOTE: This removes duplicate keys *first*
                            #   so start position might have changed ?
                            del self[k]
                self._sequence = (self._sequence[:pos] + newkeys +
                    self._sequence[pos:])
                dict.update(self, val)
            else:
                # extended slice
                # length of new slice must be the same as the one being
                # replaced
                if len(keys) != len(val):
                    raise ValueError('attempt to assign sequence of size %s '
                        'to extended slice of size %s' % (len(val), len(keys)))
                # FIXME: efficiency ?
                del self[key]
                item_list = zip(indexes, val.items())
                # smallest indexes first - higher indexes not guaranteed to
                # exist
                item_list.sort()
                for pos, (newkey, newval) in item_list:
                    if self.strict and newkey in self:
                        raise ValueError('slice assignment must be from unique'
                        ' keys')
                    self.insert(pos, newkey, newval)
        else:
            if not self.has_key(key):
                self._sequence.append(key)
            dict.__setitem__(self, key, val)

    def __getitem__(self, key):
        """
        Allows slicing. Returns an OrderedDict if you slice.
        >>> b = OrderedDict([(7, 0), (6, 1), (5, 2), (4, 3), (3, 4), (2, 5), (1, 6)])
        >>> b[::-1]
        OrderedDict([(1, 6), (2, 5), (3, 4), (4, 3), (5, 2), (6, 1), (7, 0)])
        >>> b[2:5]
        OrderedDict([(5, 2), (4, 3), (3, 4)])
        >>> type(b[2:4])
        <class '__main__.OrderedDict'>
        """
        if isinstance(key, SliceType):
            # FIXME: does this raise the error we want ?
            keys = self._sequence[key]
            # FIXME: efficiency ?
            return OrderedDict([(entry, self[entry]) for entry in keys])
        else:
            return dict.__getitem__(self, key)

    __str__ = __repr__

    def __setattr__(self, name, value):
        """
        Implemented so that accesses to ``sequence`` raise a warning and are
        diverted to the new ``setkeys`` method.
        """
        if name == 'sequence':
            warn('use of sequence attribute is deprecated. Use keys method '
                'instead.', DeprecationWarning)
            # NOTE: doesn't return anything
            self.setkeys(value)
        else:
            # FIXME: do we want to allow arbitrary setting of attributes ?
            #   or do we want to manage it ?
            object.__setattr__(self, name, value)

    def __getattr__(self, name):
        """
        Implemented so that access to ``sequence`` raises a warning.
        
        >>> d = OrderedDict()
        >>> d.sequence
        []
        """
        if name == 'sequence':
            warn('use of sequence attribute is deprecated. Use keys method '
                'instead.', DeprecationWarning)
            # NOTE: Still (currently) returns a direct reference. Need to
            #   because code that uses sequence will expect to be able to
            #   mutate it in place.
            return self._sequence
        else:
            # raise the appropriate error
            raise AttributeError("OrderedDict has no attribute '%s'" % name)

    def __deepcopy__(self, memo):
        """
        To allow deepcopy to work with OrderedDict.
        
        >>> from copy import deepcopy
        >>> a = OrderedDict([(1, 1), (2, 2), (3, 3)])
        >>> a['test'] = {}
        >>> b = deepcopy(a)
        >>> b == a
        1
        >>> b is a
        0
        >>> a['test'] is b['test']
        0
        """
        from copy import deepcopy
        return self.__class__(deepcopy(self.items(), memo), self.strict)


### Read-only methods ###

    def copy(self):
        """
        >>> OrderedDict(((1, 3), (3, 2), (2, 1))).copy()
        OrderedDict([(1, 3), (3, 2), (2, 1)])
        """
        return OrderedDict(self)

    def items(self):
        """
        ``items`` returns a list of tuples representing all the 
        ``(key, value)`` pairs in the dictionary.
        
        >>> d = OrderedDict(((1, 3), (3, 2), (2, 1)))
        >>> d.items()
        [(1, 3), (3, 2), (2, 1)]
        >>> d.clear()
        >>> d.items()
        []
        """
        return zip(self._sequence, self.values())

    def keys(self):
        """
        Return a list of keys in the ``OrderedDict``.
        
        >>> d = OrderedDict(((1, 3), (3, 2), (2, 1)))
        >>> d.keys()
        [1, 3, 2]
        """
        return self._sequence[:]

    def values(self, values=None):
        """
        Return a list of all the values in the OrderedDict.
        
        Optionally you can pass in a list of values, which will replace the
        current list. The value list must be the same len as the OrderedDict.
        
        >>> d = OrderedDict(((1, 3), (3, 2), (2, 1)))
        >>> d.values()
        [3, 2, 1]
        """
        return [self[key] for key in self._sequence]

    def iteritems(self):
        """
        >>> ii = OrderedDict(((1, 3), (3, 2), (2, 1))).iteritems()
        >>> ii.next()
        (1, 3)
        >>> ii.next()
        (3, 2)
        >>> ii.next()
        (2, 1)
        >>> ii.next()
        Traceback (most recent call last):
        StopIteration
        """
        def make_iter(self=self):
            keys = self.iterkeys()
            while True:
                key = keys.next()
                yield (key, self[key])
        return make_iter()

    def iterkeys(self):
        """
        >>> ii = OrderedDict(((1, 3), (3, 2), (2, 1))).iterkeys()
        >>> ii.next()
        1
        >>> ii.next()
        3
        >>> ii.next()
        2
        >>> ii.next()
        Traceback (most recent call last):
        StopIteration
        """
        return iter(self._sequence)

    __iter__ = iterkeys

    def itervalues(self):
        """
        >>> iv = OrderedDict(((1, 3), (3, 2), (2, 1))).itervalues()
        >>> iv.next()
        3
        >>> iv.next()
        2
        >>> iv.next()
        1
        >>> iv.next()
        Traceback (most recent call last):
        StopIteration
        """
        def make_iter(self=self):
            keys = self.iterkeys()
            while True:
                yield self[keys.next()]
        return make_iter()

### Read-write methods ###

    def clear(self):
        """
        >>> d = OrderedDict(((1, 3), (3, 2), (2, 1)))
        >>> d.clear()
        >>> d
        OrderedDict([])
        """
        dict.clear(self)
        self._sequence = []

    def pop(self, key, *args):
        """
        No dict.pop in Python 2.2, gotta reimplement it
        
        >>> d = OrderedDict(((1, 3), (3, 2), (2, 1)))
        >>> d.pop(3)
        2
        >>> d
        OrderedDict([(1, 3), (2, 1)])
        >>> d.pop(4)
        Traceback (most recent call last):
        KeyError: 4
        >>> d.pop(4, 0)
        0
        >>> d.pop(4, 0, 1)
        Traceback (most recent call last):
        TypeError: pop expected at most 2 arguments, got 3
        """
        if len(args) > 1:
            raise TypeError, ('pop expected at most 2 arguments, got %s' %
                (len(args) + 1))
        if key in self:
            val = self[key]
            del self[key]
        else:
            try:
                val = args[0]
            except IndexError:
                raise KeyError(key)
        return val

    def popitem(self, i=-1):
        """
        Delete and return an item specified by index, not a random one as in
        dict. The index is -1 by default (the last item).
        
        >>> d = OrderedDict(((1, 3), (3, 2), (2, 1)))
        >>> d.popitem()
        (2, 1)
        >>> d
        OrderedDict([(1, 3), (3, 2)])
        >>> d.popitem(0)
        (1, 3)
        >>> OrderedDict().popitem()
        Traceback (most recent call last):
        KeyError: 'popitem(): dictionary is empty'
        >>> d.popitem(2)
        Traceback (most recent call last):
        IndexError: popitem(): index 2 not valid
        """
        if not self._sequence:
            raise KeyError('popitem(): dictionary is empty')
        try:
            key = self._sequence[i]
        except IndexError:
            raise IndexError('popitem(): index %s not valid' % i)
        return (key, self.pop(key))

    def setdefault(self, key, defval = None):
        """
        >>> d = OrderedDict(((1, 3), (3, 2), (2, 1)))
        >>> d.setdefault(1)
        3
        >>> d.setdefault(4) is None
        1
        >>> d
        OrderedDict([(1, 3), (3, 2), (2, 1), (4, None)])
        >>> d.setdefault(5, 0)
        0
        >>> d
        OrderedDict([(1, 3), (3, 2), (2, 1), (4, None), (5, 0)])
        """
        if key in self:
            return self[key]
        else:
            self[key] = defval
            return defval

    def update(self, from_od):
        """
        Update from another OrderedDict or sequence of (key, value) pairs
        
        >>> d = OrderedDict()
        >>> d.update(OrderedDict(((1, 3), (3, 2), (2, 1))))
        >>> d
        OrderedDict([(1, 3), (3, 2), (2, 1)])
        >>> d.update({4: 4})
        Traceback (most recent call last):
        TypeError: undefined order, cannot get items from dict
        >>> d.update((4, 4))
        Traceback (most recent call last):
        TypeError: cannot convert dictionary update sequence element #0 to a sequence
        """
        if isinstance(from_od, OrderedDict):
            for key, val in from_od.items():
                self[key] = val
        elif isinstance(from_od, dict):
            # we lose compatibility with other ordered dict types this way
            raise TypeError('undefined order, cannot get items from dict')
        else:
            idx = 0
            # sequence of 2-item sequences, or error
            for item in from_od:
                try:
                    key, val = item
                except TypeError:
                    raise TypeError('cannot convert dictionary update'
                        ' sequence element #%d to a sequence' % idx)
                self[key] = val
                idx += 1

    def setitems(self, items):
        """
        This method allows you to set the items in the dict.
        
        It takes a list of tuples - of the same sort returned by the ``items``
        method.
        
        >>> d = OrderedDict()
        >>> d.setitems(((3, 1), (2, 3), (1, 2)))
        >>> d
        OrderedDict([(3, 1), (2, 3), (1, 2)])
        """
        self.clear()
        # FIXME: this allows you to pass in an OrderedDict as well :-)
        self.update(items)

    def setkeys(self, keys):
        """
        ``setkeys`` all ows you to pass in a new list of keys which will
        replace the current set. This must contain the same set of keys, but
        need not be in the same order.
        
        If you pass in new keys that don't match, a ``KeyError`` will be
        raised.
        
        >>> d = OrderedDict(((1, 3), (3, 2), (2, 1)))
        >>> d.keys()
        [1, 3, 2]
        >>> d.setkeys((1, 2, 3))
        >>> d
        OrderedDict([(1, 3), (2, 1), (3, 2)])
        >>> d.setkeys(['a', 'b', 'c'])
        Traceback (most recent call last):
        KeyError: 'Keylist is not the same as current keylist.'
        """
        # FIXME: Efficiency ? (use set for Python 2.4 :-)
        # NOTE: list(keys) rather than keys[:] because keys[:] returns
        #   a tuple, if keys is a tuple.
        kcopy = list(keys)
        kcopy.sort()
        self._sequence.sort()
        if kcopy != self._sequence:
            raise KeyError('Keylist is not the same as current keylist.')
        # NOTE: This makes the _sequence attribute a new object, instead
        #       of changing it in place.
        # FIXME: efficiency ?
        self._sequence = list(keys)

    def setvalues(self, values):
        """
        You can pass in a list of values, which will replace the
        current list. The value list must be the same len as the OrderedDict.
        
        (Or a ``ValueError`` is raised.)
        
        >>> d = OrderedDict(((1, 3), (3, 2), (2, 1)))
        >>> d.setvalues((1, 2, 3))
        >>> d
        OrderedDict([(1, 1), (3, 2), (2, 3)])
        >>> d.setvalues([6])
        Traceback (most recent call last):
        ValueError: Value list is not the same length as the OrderedDict.
        """
        if len(values) != len(self):
            # FIXME: correct error to raise ?
            raise ValueError('Value list is not the same length as the '
                'OrderedDict.')
        self.update(zip(self, values))

### Sequence Methods ###

    def index(self, key):
        """
        Return the position of the specified key in the OrderedDict.
        
        >>> d = OrderedDict(((1, 3), (3, 2), (2, 1)))
        >>> d.index(3)
        1
        >>> d.index(4)
        Traceback (most recent call last):
        ValueError: list.index(x): x not in list
        """
        return self._sequence.index(key)

    def insert(self, index, key, value):
        """
        Takes ``index``, ``key``, and ``value`` as arguments.
        
        Sets ``key`` to ``value``, so that ``key`` is at position ``index`` in
        the OrderedDict.
        
        >>> d = OrderedDict(((1, 3), (3, 2), (2, 1)))
        >>> d.insert(0, 4, 0)
        >>> d
        OrderedDict([(4, 0), (1, 3), (3, 2), (2, 1)])
        >>> d.insert(0, 2, 1)
        >>> d
        OrderedDict([(2, 1), (4, 0), (1, 3), (3, 2)])
        >>> d.insert(8, 8, 1)
        >>> d
        OrderedDict([(2, 1), (4, 0), (1, 3), (3, 2), (8, 1)])
        """
        if key in self:
            # FIXME: efficiency ?
            del self[key]
        self._sequence.insert(index, key)
        dict.__setitem__(self, key, value)

    def reverse(self):
        """
        Reverse the order of the OrderedDict.
        
        >>> d = OrderedDict(((1, 3), (3, 2), (2, 1)))
        >>> d.reverse()
        >>> d
        OrderedDict([(2, 1), (3, 2), (1, 3)])
        """
        self._sequence.reverse()

    def sort(self, *args, **kwargs):
        """
        Sort the key order in the OrderedDict.
        
        This method takes the same arguments as the ``list.sort`` method on
        your version of Python.
        
        >>> d = OrderedDict(((4, 1), (2, 2), (3, 3), (1, 4)))
        >>> d.sort()
        >>> d
        OrderedDict([(1, 4), (2, 2), (3, 3), (4, 1)])
        """
        self._sequence.sort(*args, **kwargs)

class _keys(object):
    # FIXME: should this object be a subclass of list ?
    """
    Custom object for accessing the keys of an OrderedDict.
    
    Can be called like the normal ``OrderedDict.keys`` method, but also
    supports indexing and sequence methods.
    """

    def __init__(self, main):
        self._main = main

    def __call__(self):
        """Pretend to be the keys method."""
        return self._main._keys()

    def __getitem__(self, index):
        """Fetch the key at position i."""
        # NOTE: this automatically supports slicing :-)
        return self._main._sequence[index]

    def __setitem__(self, index, name):
        """
        You cannot assign to keys, but you can do slice assignment to re-order
        them.
        
        You can only do slice assignment if the new set of keys is a reordering
        of the original set.
        """
        if isinstance(index, SliceType):
            # FIXME: efficiency ?
            # check length is the same
            indexes = range(len(self._main._sequence))[index]
            if len(indexes) != len(name):
                raise ValueError('attempt to assign sequence of size %s '
                    'to slice of size %s' % (len(name), len(indexes)))
            # check they are the same keys
            # FIXME: Use set
            old_keys = self._main._sequence[index]
            new_keys = list(name)
            old_keys.sort()
            new_keys.sort()
            if old_keys != new_keys:
                raise KeyError('Keylist is not the same as current keylist.')
            orig_vals = [self._main[k] for k in name]
            del self._main[index]
            vals = zip(indexes, name, orig_vals)
            vals.sort()
            for i, k, v in vals:
                if self._main.strict and k in self._main:
                    raise ValueError('slice assignment must be from '
                        'unique keys')
                self._main.insert(i, k, v)
        else:
            raise ValueError('Cannot assign to keys')

    ### following methods pinched from UserList and adapted ###
    def __repr__(self): return repr(self._main._sequence)

    # FIXME: do we need to check if we are comparing with another ``_keys``
    #   object ? (like the __cast method of UserList)
    def __lt__(self, other): return self._main._sequence <  other
    def __le__(self, other): return self._main._sequence <= other
    def __eq__(self, other): return self._main._sequence == other
    def __ne__(self, other): return self._main._sequence != other
    def __gt__(self, other): return self._main._sequence >  other
    def __ge__(self, other): return self._main._sequence >= other
    # FIXME: do we need __cmp__ as well as rich comparisons ?
    def __cmp__(self, other): return cmp(self._main._sequence, other)

    def __contains__(self, item): return item in self._main._sequence
    def __len__(self): return len(self._main._sequence)
    def __iter__(self): return self._main.iterkeys()
    def count(self, item): return self._main._sequence.count(item)
    def index(self, item, *args): return self._main._sequence.index(item, *args)
    def reverse(self): self._main._sequence.reverse()
    def sort(self, *args, **kwds): self._main._sequence.sort(*args, **kwds)
    def __mul__(self, n): return self._main._sequence*n
    __rmul__ = __mul__
    def __add__(self, other): return self._main._sequence + other
    def __radd__(self, other): return other + self._main._sequence

    ## following methods not implemented for keys ##
    def __delitem__(self, i): raise TypeError('Can\'t delete items from keys')
    def __iadd__(self, other): raise TypeError('Can\'t add in place to keys')
    def __imul__(self, n): raise TypeError('Can\'t multiply keys in place')
    def append(self, item): raise TypeError('Can\'t append items to keys')
    def insert(self, i, item): raise TypeError('Can\'t insert items into keys')
    def pop(self, i=-1): raise TypeError('Can\'t pop items from keys')
    def remove(self, item): raise TypeError('Can\'t remove items from keys')
    def extend(self, other): raise TypeError('Can\'t extend keys')

class _items(object):
    """
    Custom object for accessing the items of an OrderedDict.
    
    Can be called like the normal ``OrderedDict.items`` method, but also
    supports indexing and sequence methods.
    """

    def __init__(self, main):
        self._main = main

    def __call__(self):
        """Pretend to be the items method."""
        return self._main._items()

    def __getitem__(self, index):
        """Fetch the item at position i."""
        if isinstance(index, SliceType):
            # fetching a slice returns an OrderedDict
            return self._main[index].items()
        key = self._main._sequence[index]
        return (key, self._main[key])

    def __setitem__(self, index, item):
        """Set item at position i to item."""
        if isinstance(index, SliceType):
            # NOTE: item must be an iterable (list of tuples)
            self._main[index] = OrderedDict(item)
        else:
            # FIXME: Does this raise a sensible error ?
            orig = self._main.keys[index]
            key, value = item
            if self._main.strict and key in self and (key != orig):
                raise ValueError('slice assignment must be from '
                        'unique keys')
            # delete the current one
            del self._main[self._main._sequence[index]]
            self._main.insert(index, key, value)

    def __delitem__(self, i):
        """Delete the item at position i."""
        key = self._main._sequence[i]
        if isinstance(i, SliceType):
            for k in key:
                # FIXME: efficiency ?
                del self._main[k]
        else:
            del self._main[key]

    ### following methods pinched from UserList and adapted ###
    def __repr__(self): return repr(self._main.items())

    # FIXME: do we need to check if we are comparing with another ``_items``
    #   object ? (like the __cast method of UserList)
    def __lt__(self, other): return self._main.items() <  other
    def __le__(self, other): return self._main.items() <= other
    def __eq__(self, other): return self._main.items() == other
    def __ne__(self, other): return self._main.items() != other
    def __gt__(self, other): return self._main.items() >  other
    def __ge__(self, other): return self._main.items() >= other
    def __cmp__(self, other): return cmp(self._main.items(), other)

    def __contains__(self, item): return item in self._main.items()
    def __len__(self): return len(self._main._sequence) # easier :-)
    def __iter__(self): return self._main.iteritems()
    def count(self, item): return self._main.items().count(item)
    def index(self, item, *args): return self._main.items().index(item, *args)
    def reverse(self): self._main.reverse()
    def sort(self, *args, **kwds): self._main.sort(*args, **kwds)
    def __mul__(self, n): return self._main.items()*n
    __rmul__ = __mul__
    def __add__(self, other): return self._main.items() + other
    def __radd__(self, other): return other + self._main.items()

    def append(self, item):
        """Add an item to the end."""
        # FIXME: this is only append if the key isn't already present
        key, value = item
        self._main[key] = value

    def insert(self, i, item):
        key, value = item
        self._main.insert(i, key, value)

    def pop(self, i=-1):
        key = self._main._sequence[i]
        return (key, self._main.pop(key))

    def remove(self, item):
        key, value = item
        try:
            assert value == self._main[key]
        except (KeyError, AssertionError):
            raise ValueError('ValueError: list.remove(x): x not in list')
        else:
            del self._main[key]

    def extend(self, other):
        # FIXME: is only a true extend if none of the keys already present
        for item in other:
            key, value = item
            self._main[key] = value

    def __iadd__(self, other):
        self.extend(other)

    ## following methods not implemented for items ##

    def __imul__(self, n): raise TypeError('Can\'t multiply items in place')


class _values(object):
    """
    Custom object for accessing the values of an OrderedDict.
    
    Can be called like the normal ``OrderedDict.values`` method, but also
    supports indexing and sequence methods.
    """

    def __init__(self, main):
        self._main = main

    def __call__(self):
        """Pretend to be the values method."""
        return self._main._values()

    def __getitem__(self, index):
        """Fetch the value at position i."""
        if isinstance(index, SliceType):
            return [self._main[key] for key in self._main._sequence[index]]
        else:
            return self._main[self._main._sequence[index]]

    def __setitem__(self, index, value):
        """
        Set the value at position i to value.
        
        You can only do slice assignment to values if you supply a sequence of
        equal length to the slice you are replacing.
        """
        if isinstance(index, SliceType):
            keys = self._main._sequence[index]
            if len(keys) != len(value):
                raise ValueError('attempt to assign sequence of size %s '
                    'to slice of size %s' % (len(name), len(keys)))
            # FIXME: efficiency ?  Would be better to calculate the indexes
            #   directly from the slice object
            # NOTE: the new keys can collide with existing keys (or even
            #   contain duplicates) - these will overwrite
            for key, val in zip(keys, value):
                self._main[key] = val
        else:
            self._main[self._main._sequence[index]] = value

    ### following methods pinched from UserList and adapted ###
    def __repr__(self): return repr(self._main.values())

    # FIXME: do we need to check if we are comparing with another ``_values``
    #   object ? (like the __cast method of UserList)
    def __lt__(self, other): return self._main.values() <  other
    def __le__(self, other): return self._main.values() <= other
    def __eq__(self, other): return self._main.values() == other
    def __ne__(self, other): return self._main.values() != other
    def __gt__(self, other): return self._main.values() >  other
    def __ge__(self, other): return self._main.values() >= other
    def __cmp__(self, other): return cmp(self._main.values(), other)

    def __contains__(self, item): return item in self._main.values()
    def __len__(self): return len(self._main._sequence) # easier :-)
    def __iter__(self): return self._main.itervalues()
    def count(self, item): return self._main.values().count(item)
    def index(self, item, *args): return self._main.values().index(item, *args)

    def reverse(self):
        """Reverse the values"""
        vals = self._main.values()
        vals.reverse()
        # FIXME: efficiency
        self[:] = vals

    def sort(self, *args, **kwds):
        """Sort the values."""
        vals = self._main.values()
        vals.sort(*args, **kwds)
        self[:] = vals

    def __mul__(self, n): return self._main.values()*n
    __rmul__ = __mul__
    def __add__(self, other): return self._main.values() + other
    def __radd__(self, other): return other + self._main.values()

    ## following methods not implemented for values ##
    def __delitem__(self, i): raise TypeError('Can\'t delete items from values')
    def __iadd__(self, other): raise TypeError('Can\'t add in place to values')
    def __imul__(self, n): raise TypeError('Can\'t multiply values in place')
    def append(self, item): raise TypeError('Can\'t append items to values')
    def insert(self, i, item): raise TypeError('Can\'t insert items into values')
    def pop(self, i=-1): raise TypeError('Can\'t pop items from values')
    def remove(self, item): raise TypeError('Can\'t remove items from values')
    def extend(self, other): raise TypeError('Can\'t extend values')


class SequenceOrderedDict(OrderedDict):
    """
    Experimental version of OrderedDict that has a custom object for ``keys``,
    ``values``, and ``items``.
    
    These are callable sequence objects that work as methods, or can be
    manipulated directly as sequences.
    
    Test for ``keys``, ``items`` and ``values``.
    
    >>> d = SequenceOrderedDict(((1, 2), (2, 3), (3, 4)))
    >>> d
    SequenceOrderedDict([(1, 2), (2, 3), (3, 4)])
    >>> d.keys
    [1, 2, 3]
    >>> d.keys()
    [1, 2, 3]
    >>> d.setkeys((3, 2, 1))
    >>> d
    SequenceOrderedDict([(3, 4), (2, 3), (1, 2)])
    >>> d.setkeys((1, 2, 3))
    >>> d.keys[0]
    1
    >>> d.keys[:]
    [1, 2, 3]
    >>> d.keys[-1]
    3
    >>> d.keys[-2]
    2
    >>> d.keys[0:2] = [2, 1]
    >>> d
    SequenceOrderedDict([(2, 3), (1, 2), (3, 4)])
    >>> d.keys.reverse()
    >>> d.keys
    [3, 1, 2]
    >>> d.keys = [1, 2, 3]
    >>> d
    SequenceOrderedDict([(1, 2), (2, 3), (3, 4)])
    >>> d.keys = [3, 1, 2]
    >>> d
    SequenceOrderedDict([(3, 4), (1, 2), (2, 3)])
    >>> a = SequenceOrderedDict()
    >>> b = SequenceOrderedDict()
    >>> a.keys == b.keys
    1
    >>> a['a'] = 3
    >>> a.keys == b.keys
    0
    >>> b['a'] = 3
    >>> a.keys == b.keys
    1
    >>> b['b'] = 3
    >>> a.keys == b.keys
    0
    >>> a.keys > b.keys
    0
    >>> a.keys < b.keys
    1
    >>> 'a' in a.keys
    1
    >>> len(b.keys)
    2
    >>> 'c' in d.keys
    0
    >>> 1 in d.keys
    1
    >>> [v for v in d.keys]
    [3, 1, 2]
    >>> d.keys.sort()
    >>> d.keys
    [1, 2, 3]
    >>> d = SequenceOrderedDict(((1, 2), (2, 3), (3, 4)), strict=True)
    >>> d.keys[::-1] = [1, 2, 3]
    >>> d
    SequenceOrderedDict([(3, 4), (2, 3), (1, 2)])
    >>> d.keys[:2]
    [3, 2]
    >>> d.keys[:2] = [1, 3]
    Traceback (most recent call last):
    KeyError: 'Keylist is not the same as current keylist.'

    >>> d = SequenceOrderedDict(((1, 2), (2, 3), (3, 4)))
    >>> d
    SequenceOrderedDict([(1, 2), (2, 3), (3, 4)])
    >>> d.values
    [2, 3, 4]
    >>> d.values()
    [2, 3, 4]
    >>> d.setvalues((4, 3, 2))
    >>> d
    SequenceOrderedDict([(1, 4), (2, 3), (3, 2)])
    >>> d.values[::-1]
    [2, 3, 4]
    >>> d.values[0]
    4
    >>> d.values[-2]
    3
    >>> del d.values[0]
    Traceback (most recent call last):
    TypeError: Can't delete items from values
    >>> d.values[::2] = [2, 4]
    >>> d
    SequenceOrderedDict([(1, 2), (2, 3), (3, 4)])
    >>> 7 in d.values
    0
    >>> len(d.values)
    3
    >>> [val for val in d.values]
    [2, 3, 4]
    >>> d.values[-1] = 2
    >>> d.values.count(2)
    2
    >>> d.values.index(2)
    0
    >>> d.values[-1] = 7
    >>> d.values
    [2, 3, 7]
    >>> d.values.reverse()
    >>> d.values
    [7, 3, 2]
    >>> d.values.sort()
    >>> d.values
    [2, 3, 7]
    >>> d.values.append('anything')
    Traceback (most recent call last):
    TypeError: Can't append items to values
    >>> d.values = (1, 2, 3)
    >>> d
    SequenceOrderedDict([(1, 1), (2, 2), (3, 3)])
    
    >>> d = SequenceOrderedDict(((1, 2), (2, 3), (3, 4)))
    >>> d
    SequenceOrderedDict([(1, 2), (2, 3), (3, 4)])
    >>> d.items()
    [(1, 2), (2, 3), (3, 4)]
    >>> d.setitems([(3, 4), (2 ,3), (1, 2)])
    >>> d
    SequenceOrderedDict([(3, 4), (2, 3), (1, 2)])
    >>> d.items[0]
    (3, 4)
    >>> d.items[:-1]
    [(3, 4), (2, 3)]
    >>> d.items[1] = (6, 3)
    >>> d.items
    [(3, 4), (6, 3), (1, 2)]
    >>> d.items[1:2] = [(9, 9)]
    >>> d
    SequenceOrderedDict([(3, 4), (9, 9), (1, 2)])
    >>> del d.items[1:2]
    >>> d
    SequenceOrderedDict([(3, 4), (1, 2)])
    >>> (3, 4) in d.items
    1
    >>> (4, 3) in d.items
    0
    >>> len(d.items)
    2
    >>> [v for v in d.items]
    [(3, 4), (1, 2)]
    >>> d.items.count((3, 4))
    1
    >>> d.items.index((1, 2))
    1
    >>> d.items.index((2, 1))
    Traceback (most recent call last):
    ValueError: list.index(x): x not in list
    >>> d.items.reverse()
    >>> d.items
    [(1, 2), (3, 4)]
    >>> d.items.reverse()
    >>> d.items.sort()
    >>> d.items
    [(1, 2), (3, 4)]
    >>> d.items.append((5, 6))
    >>> d.items
    [(1, 2), (3, 4), (5, 6)]
    >>> d.items.insert(0, (0, 0))
    >>> d.items
    [(0, 0), (1, 2), (3, 4), (5, 6)]
    >>> d.items.insert(-1, (7, 8))
    >>> d.items
    [(0, 0), (1, 2), (3, 4), (7, 8), (5, 6)]
    >>> d.items.pop()
    (5, 6)
    >>> d.items
    [(0, 0), (1, 2), (3, 4), (7, 8)]
    >>> d.items.remove((1, 2))
    >>> d.items
    [(0, 0), (3, 4), (7, 8)]
    >>> d.items.extend([(1, 2), (5, 6)])
    >>> d.items
    [(0, 0), (3, 4), (7, 8), (1, 2), (5, 6)]
    """

    def __init__(self, init_val=(), strict=True):
        OrderedDict.__init__(self, init_val, strict=strict)
        self._keys = self.keys
        self._values = self.values
        self._items = self.items
        self.keys = _keys(self)
        self.values = _values(self)
        self.items = _items(self)
        self._att_dict = {'keys': self.setkeys,
            'items': self.setitems,
            'values': self.setvalues
            }

    def __setattr__(self, name, value):
        """Protect keys, items, and values."""
        if not '_att_dict' in self.__dict__:
            object.__setattr__(self, name, value)
        else:
            try:
                fun = self._att_dict[name]
            except KeyError:
                OrderedDict.__setattr__(self, name, value)
            else:
                fun(value)

if __name__ == '__main__':
    # run the code tests in doctest format
    import doctest
    m = sys.modules.get('__main__')
    globs = m.__dict__.copy()
    globs.update({
        'INTP_VER': INTP_VER,
    })
    doctest.testmod(m, globs=globs)

"""
    ISSUES
    ======
    
    Slicing doesn't work in Python 2.2. This is because in 2.2, you can't index
    a sequence with a slice object. Could be implemented with ``operator``
    slicing functions (which don't support extended slices).
    
    TODO
    ====
    
    Addition (``__add__``) ? (This would just be syntactic sugar for
    ``update``)
    
    Implement the Python 2.4 arguments (``key`` and ``reverse``) for ``sort``
    for Python 2.2 and 2.3 ? (So the interface is stable)
    
    Add sequence methods ``move`` and ``rename`` ? (To change the name of a key
    at a specific index, and change the index of a key from one position to
    another)
    
    Allow assignment to keys (in ``SequenceOrderedDict``) to rename a key ?
    
    Do I *need* to implement ``__cmp__`` - I don't *think* so ?
    
    Allow slice assignment to ``OrderedDict`` (and `possibly
    ``SequenceOrderedDict.items``) from list of tuples as well as from an
    ``OrderedDict`` ?
    
    CHANGELOG
    =========
    
    2005/12/17
    ----------
    
    You can now test for equality and inequality with objects (except for
    dictionaries for which it is undefined). This allows you to do tests like :
    ::
    
        OrderedDict() == False
    
    Added the ``strict`` keyword, which raises a ``ValueError`` if you do slice
    assignment with keys that are already in the dictionary.
    
    Assignment to ``keys`` in ``SequenceOrderedDict`` is now only for
    re-ordering the keys.
    
    Fixed bug where slice assignment to ``keys`` could lose information. (and
    optimised by slicing ranges to get the indexes we are assigning to instead
    of indexing each key).
    
    You change keys, items, and values through new methods ``setkeys``,
    ``setitems``, and ``setvalues`` methods.
    
    Minor changes, thanks to Christoph Zwerschke for suggestions.
    
    Added ``__deepcopy__`` method (previously deepcopy failed).
    
    CHanged use of ``slice`` to ``types.SliceType`` for Python 2.2.
    
    0.2.1
    
    
    2005/12/02
    ----------
    
    Fixed bugs in ``__getattr__`` and ``popitem``
    
    Optimisation in ``OrderedDict.__init__`` when creating an instance from an
    ``OrderedDict``
    
    Changed ``FancyODict`` to ``SequenceOrderedDict``
    
    Implemented new ``__repr__``
    
    0.2.0
    
    2005/12/01
    ----------
    
    Added index to ``OrderedDict.popitem``
    
    2005/11/30
    ----------
    
    Implemented ``FancyODict``, which has ``keys``, ``items``, ``values`` as
    custom, callable, sequence objects.
    
    2005/11/26
    ----------
    
    By Michael Foord - from suggestions on comp.lang.python
    
    Hidden the ``sequence`` attribute
    
    ``items``, ``keys``, ``values`` can now take a list to replace the current
    keys, values, or items
    
    Implemented slicing (including deleting a slice and assigning to a slice)
    
    Implemented sequence methods ``sort``, ``reverse``, ``insert``, ``index``
    
    2005/09/10
    ----------
    
    By Nicola Larosa, based on code from Tim Wegener
      <twegener AT radlogic DOT com DOT au>
    
    Create itervalues and iteritems without creating the list up-front
    
    Added doctests for iter methods, and others.
    
    Optimized __setitem__ to be O(1) rather than O(N)
    
    Removed redefined methods that did not alter dict method behaviour,
      related doctests moved to the class docstring
    
    Added support for sequences of (key, value) pairs to update
    
    Removed redundant condition from __eq__
    
    Removed incorrect implementation of __str__
    
    2005/08/28
    ----------
    
    By Michael Foord
    
    Added __all__
    
    More than two arguments to ``pop`` now raises an error
    
    Version 0.1.0 finalised
    
    2005/08/13
    ----------
    
    By Nicola Larosa
    
    Added doctests everywhere, fixed much part of implementation
    
    Added comments at top, other doc vars
    
    2005/08/01
    ----------
    
    By Michael Foord
    
    Type tests changed to isinstance
    
    _keys changed to sequence attribute
    
    Allowed creating a dictionary by passing keyword arguments
    
    Shortened __repr__
    
    Fixed bug in popitem
    
    Other minor changes
"""
