| # http://code.activestate.com/recipes/576693/ (r9) | |
| # Created by Raymond Hettinger on Wed, 18 Mar 2009 (MIT) | |
| # | |
| # Backport of OrderedDict() class that runs on Python 2.4, 2.5, 2.6, 2.7 | |
| # and pypy. | |
| # Passes Python2.7's test suite and incorporates all the latest updates. | |
| # | |
| try: | |
| from thread import get_ident as _get_ident | |
| except ImportError: | |
| from dummy_thread import get_ident as _get_ident | |
| try: | |
| from _abcoll import KeysView, ValuesView, ItemsView | |
| except ImportError: | |
| pass | |
| 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 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] | |
| 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) | |
| 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 -- | |
| def keys(self): | |
| 'od.keys() -> list of keys in od' | |
| return list(self) | |
| def values(self): | |
| 'od.values() -> list of values in od' | |
| return [self[key] for key in self] | |
| def items(self): | |
| 'od.items() -> list of (key, value) pairs in od' | |
| return [(key, self[key]) for key in self] | |
| def iterkeys(self): | |
| 'od.iterkeys() -> an iterator over the keys in od' | |
| return iter(self) | |
| def itervalues(self): | |
| 'od.itervalues -> an iterator over the values in od' | |
| for k in self: | |
| yield self[k] | |
| def iteritems(self): | |
| 'od.iteritems -> an iterator over the (key, value) items in od' | |
| for k in self: | |
| yield (k, self[k]) | |
| 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() | |
| 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 | |
| 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,) | |
| def copy(self): | |
| 'od.copy() -> a shallow copy of od' | |
| return self.__class__(self) | |
| @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 -- | |
| def viewkeys(self): | |
| "od.viewkeys() -> a set-like object providing a view on od's keys" | |
| return KeysView(self) | |
| def viewvalues(self): | |
| "od.viewvalues() -> an object providing a view on od's values" | |
| return ValuesView(self) | |
| def viewitems(self): | |
| "od.viewitems() -> a set-like object providing a view on od's items" | |
| return ItemsView(self) | |