try:
from thread import get_ident as _get_ident
except ImportError:
try:
from dummy_thread import get_ident as _get_ident
except ImportError:
pass
try:
from _abcoll import KeysView, ValuesView, ItemsView
except ImportError:
pass
[docs]class OrderedDict(dict):
""" Dictionary that remembers insertion order, for Python 2.6 and below
Code from: http://code.activestate.com/recipes/576693/
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 for regular dictionaries.
The internal self.__map dictionary 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).
Each link is stored as a list of length three: [PREV, NEXT, KEY]. """
def __init__(self, *args, **kwds):
# Initialize an ordered dictionary. Signature is the same as for
# regular dictionaries, but keyword arguments are not recommended
# because their insertion order is arbitrary.
if len(args) > 1:
raise TypeError('expected at most 1 arguments, got %d' % len(args))
try:
self.__root
except AttributeError:
self.__root = root = [] # sentinel node
root[:] = [root, root, None]
self.__map = {}
self.__update(*args, **kwds)
def __setitem__(self, key, value, dict_setitem=dict.__setitem__):
# od.__setitem__(i, y) <==> od[i]=y
# Setting a new item creates a new link which goes at the end of the linked
# list, and the inherited dictionary is updated with the new key/value pair.
if key not in self:
root = self.__root
last = root[0]
last[1] = root[0] = self.__map[key] = [last, root, key]
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 is
# then removed by updating the links in the predecessor and successor nodes.
dict_delitem(self, key)
link_prev, link_next, key = self.__map.pop(key)
link_prev[1] = link_next
link_next[0] = link_prev
def __iter__(self):
# od.__iter__() <==> iter(od)
root = self.__root
curr = root[1]
while curr is not root:
yield curr[2]
curr = curr[1]
def __reversed__(self):
# od.__reversed__() <==> reversed(od)
root = self.__root
curr = root[0]
while curr is not root:
yield curr[2]
curr = curr[0]
[docs] def clear(self):
# od.clear() -> None. Remove all items from od.
try:
for node in self.__map.itervalues():
del node[:]
root = self.__root
root[:] = [root, root, None]
self.__map.clear()
except AttributeError:
pass
dict.clear(self)
[docs] def popitem(self, last=True):
# od.popitem() -> (k, v), return and remove a (key, value) pair.
# 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[0]
link_prev = link[0]
link_prev[1] = root
root[0] = link_prev
else:
link = root[1]
link_next = link[1]
root[1] = link_next
link_next[0] = root
key = link[2]
del self.__map[key]
value = dict.pop(self, key)
return key, value
# -- the following methods do not depend on the internal structure --
[docs] def keys(self):
# od.keys() -> list of keys in od
return list(self)
[docs] def values(self):
# od.values() -> list of values in od
return [self[key] for key in self]
[docs] def items(self):
# od.items() -> list of (key, value) pairs in od
return [(key, self[key]) for key in self]
[docs] def iterkeys(self):
# od.iterkeys() -> an iterator over the keys in od
return iter(self)
[docs] def itervalues(self):
# od.itervalues -> an iterator over the values in od
for k in self:
yield self[k]
[docs] def iteritems(self):
# od.iteritems -> an iterator over the (key, value) items in od
for k in self:
yield (k, self[k])
[docs] def update(*args, **kwds):
# od.update(E, **F) -> None. Update od from dict/iterable E and F.
# If E is a dict instance, does: for k in E: od[k] = E[k]
# If E has a .keys() method, does: for k in E.keys(): od[k] = E[k]
# Or if E is an iterable of items, does: for k, v in E: od[k] = v
# In either case, this is followed by: for k, v in F.items(): od[k] = v
if len(args) > 2:
raise TypeError('update() takes at most 2 positional '
'arguments (%d given)' % (len(args),))
elif not args:
raise TypeError('update() takes at least 1 argument (0 given)')
self = args[0]
# Make progressively weaker assumptions about "other"
other = ()
if len(args) == 2:
other = args[1]
if isinstance(other, dict):
for key in other:
self[key] = other[key]
elif hasattr(other, 'keys'):
for key in other.keys():
self[key] = other[key]
else:
for key, value in other:
self[key] = value
for key, value in kwds.items():
self[key] = value
__update = update # let subclasses override update without breaking __init__
__marker = object()
[docs] 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.
if key in self:
result = self[key]
del self[key]
return result
if default is self.__marker:
raise KeyError(key)
return default
[docs] def setdefault(self, key, default=None):
# od.setdefault(k[,d]) -> od.get(k,d), also set od[k]=d if k not in od
if key in self:
return self[key]
self[key] = default
return default
def __repr__(self, _repr_running={}):
# od.__repr__() <==> repr(od)
call_key = id(self), _get_ident()
if call_key in _repr_running:
return '...'
_repr_running[call_key] = 1
try:
if not self:
return '%s()' % (self.__class__.__name__,)
return '%s(%r)' % (self.__class__.__name__, self.items())
finally:
del _repr_running[call_key]
def __reduce__(self):
# Return state information for pickling
items = [[k, self[k]] for k in self]
inst_dict = vars(self).copy()
for k in vars(OrderedDict()):
inst_dict.pop(k, None)
if inst_dict:
return (self.__class__, (items,), inst_dict)
return self.__class__, (items,)
[docs] def copy(self):
# od.copy() -> a shallow copy of od
return self.__class__(self)
[docs] @classmethod
def fromkeys(cls, iterable, value=None):
# OD.fromkeys(S[, v]) -> New ordered dictionary with keys from S
# and values equal to v (which defaults to None).
d = cls()
for key in iterable:
d[key] = value
return d
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 len(self)==len(other) and self.items() == other.items()
return dict.__eq__(self, other)
def __ne__(self, other):
return not self == other
# -- the following methods are only used in Python 2.7 --
[docs] def viewkeys(self):
# od.viewkeys() -> a set-like object providing a view on od's keys
return KeysView(self)
[docs] def viewvalues(self):
# od.viewvalues() -> an object providing a view on od's values
return ValuesView(self)
[docs] def viewitems(self):
# od.viewitems() -> a set-like object providing a view on od's items
return ItemsView(self)