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)])

Overrides: dict.__init__

>>> 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)])

Overrides: dict.__delitem__

>>> 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

Overrides: dict.__eq__

>>> 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

Overrides: dict.__lt__

>>> 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

Overrides: dict.__le__

>>> 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

Overrides: dict.__ne__

>>> 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

Overrides: dict.__gt__

>>> 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

Overrides: dict.__ge__

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

Overrides: dict.__repr__

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)])

Overrides: dict.__setitem__

Overrides: dict.__getitem__

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

Overrides: object.__str__

Overrides: object.__setattr__

Implemented so that access to sequence raises a warning.

>>> d = OrderedDict()
>>> d.sequence
[]

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

>>> OrderedDict(((1, 3), (3, 2), (2, 1))).copy()
OrderedDict([(1, 3), (3, 2), (2, 1)])

Returns:

a shallow copy of D

Overrides: dict.copy

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()
[]

Returns:

list of D's (key, value) pairs, as 2-tuples

Overrides: dict.items

Return a list of keys in the OrderedDict.

>>> d = OrderedDict(((1, 3), (3, 2), (2, 1)))
>>> d.keys()
[1, 3, 2]

Returns:

list of D's keys

Overrides: dict.keys

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]

Returns:

list of D's values

Overrides: dict.values

>>> 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

Returns:

an iterator over the (key, value) items of D

Overrides: dict.iteritems

>>> 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

Returns:

an iterator over the keys of D

Overrides: dict.iterkeys

>>> 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

Returns:

an iterator over the keys of D

Overrides: dict.__iter__

>>> 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

Returns:

an iterator over the values of D

Overrides: dict.itervalues

>>> d = OrderedDict(((1, 3), (3, 2), (2, 1)))
>>> d.clear()
>>> d
OrderedDict([])

Returns:

None

Overrides: dict.clear

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

Returns:

v, remove specified key and return the corresponding value

Overrides: dict.pop

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

Returns:

(k, v), remove and return some (key, value) pair as a

Overrides: dict.popitem

>>> 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)])

Returns:

D.get(k,d), also set D[k]=d if k not in D

Overrides: dict.setdefault

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

Returns:

None

Overrides: dict.update

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)])

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.'

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.

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

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)])

Reverse the order of the OrderedDict.

>>> d = OrderedDict(((1, 3), (3, 2), (2, 1)))
>>> d.reverse()
>>> d
OrderedDict([(2, 1), (3, 2), (1, 3)])

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)])