Python collections.OrderedDict.keys() Examples

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 __getattr__(self, name):
        """
        Implemented so that access to ``sequence`` raises a warning.

        >>> d = OrderedDict()
        >>> d.sequence
        []
        """
        if name == 'sequence':
            warnings.warn('Use of the sequence attribute is deprecated.'
                ' Use the 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 '%s' attribute" % name) 

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 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 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 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 __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, types.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 __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, types.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) 

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 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 __getattr__(self, name):
        """
        Implemented so that access to ``sequence`` raises a warning.

        >>> d = OrderedDict()
        >>> d.sequence
        []
        """
        if name == 'sequence':
            warnings.warn('Use of the sequence attribute is deprecated.'
                ' Use the 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 '%s' attribute" % name) 

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, types.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) 

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, types.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 __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, types.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) 

def __getattr__(self, name):
        """
        Implemented so that access to ``sequence`` raises a warning.

        >>> d = OrderedDict()
        >>> d.sequence
        []
        """
        if name == 'sequence':
            warnings.warn('Use of the sequence attribute is deprecated.'
                ' Use the 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 '%s' attribute" % name) 

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 __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, types.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) 

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

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 append(self, item): raise TypeError('Can\'t append items to keys') 

def __radd__(self, other): return other + self._main._sequence

    ## following methods not implemented for keys ## 

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

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 __delitem__(self, i): raise TypeError('Can\'t delete items from 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 __setattr__(self, name, value):
        """
        Implemented so that accesses to ``sequence`` raise a warning and are
        diverted to the new ``setkeys`` method.
        """
        if name == 'sequence':
            warnings.warn('Use of the sequence attribute is deprecated.'
                ' Use the 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 __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 extend(self, other): raise TypeError('Can\'t extend keys') 

def __iadd__(self, other): raise TypeError('Can\'t add in place to keys')