API#

This page contains auto-generated documentation from the bidict source code.

bidict#

The bidirectional mapping library for Python.


bidict by example:

>>> from bidict import bidict
>>> element_by_symbol = bidict({'H': 'hydrogen'})
>>> element_by_symbol['H']
'hydrogen'
>>> element_by_symbol.inverse['hydrogen']
'H'

Please see https://github.com/jab/bidict for the most up-to-date code and https://bidict.readthedocs.io for the most up-to-date documentation if you are reading this elsewhere.


class bidict.BidirectionalMapping#

Bases: Mapping[KT, VT]

Abstract base class for bidirectional mapping types.

Extends collections.abc.Mapping primarily by adding the (abstract) inverse property, which implementors of BidirectionalMapping should override to return a reference to the inverse BidirectionalMapping instance.

__abstractmethods__ = frozenset({'__getitem__', '__iter__', '__len__', 'inverse'})#
__class_getitem__ = <bound method GenericAlias of <class 'bidict.BidirectionalMapping'>>#
__contains__(key)#
__eq__(other)#

Return self==value.

abstract __getitem__(key)#
__hash__ = None#
classmethod __init_subclass__(*args, **kwargs)#

This method is called when a class is subclassed.

The default implementation does nothing. It may be overridden to extend subclasses.

__inverted__()[source]#

Get an iterator over the items in inverse.

This is functionally equivalent to iterating over the items in the forward mapping and inverting each one on the fly, but this provides a more efficient implementation: Assuming the already-inverted items are stored in inverse, just return an iterator over them directly.

Providing this default implementation enables external functions, particularly inverted(), to use this optimized implementation when available, instead of having to invert on the fly.

See also bidict.inverted()

Return type:

Iterator[Tuple[VT, KT]]

abstract __iter__()#
abstract __len__()#
__module__ = 'bidict'#
__orig_bases__ = (typing.Mapping[~KT, ~VT],)#
__parameters__ = (~KT, ~VT)#
__reversed__ = None#
__slots__ = ()#
classmethod __subclasshook__(C)#

Abstract classes can override this to customize issubclass().

This is invoked early on by abc.ABCMeta.__subclasscheck__(). It should return True, False or NotImplemented. If it returns NotImplemented, the normal algorithm is used. Otherwise, it overrides the normal algorithm (and the outcome is cached).

get(k[, d]) D[k] if k in D, else d.  d defaults to None.#
abstract property inverse: BidirectionalMapping[VT, KT]#

The inverse of this bidirectional mapping instance.

See also bidict.BidictBase.inverse, bidict.BidictBase.inv

Raises:

NotImplementedError – Meant to be overridden in subclasses.

items() a set-like object providing a view on D's items#
keys() a set-like object providing a view on D's keys#
values() an object providing a view on D's values#
class bidict.MutableBidirectionalMapping#

Bases: BidirectionalMapping[KT, VT], MutableMapping[KT, VT]

Abstract base class for mutable bidirectional mapping types.

__abstractmethods__ = frozenset({'__delitem__', '__getitem__', '__iter__', '__len__', '__setitem__', 'inverse'})#
__annotations__ = {}#
__class_getitem__ = <bound method GenericAlias of <class 'bidict.MutableBidirectionalMapping'>>#
__contains__(key)#
abstract __delitem__(key)#
__eq__(other)#

Return self==value.

abstract __getitem__(key)#
__hash__ = None#
classmethod __init_subclass__(*args, **kwargs)#

This method is called when a class is subclassed.

The default implementation does nothing. It may be overridden to extend subclasses.

__inverted__()#

Get an iterator over the items in inverse.

This is functionally equivalent to iterating over the items in the forward mapping and inverting each one on the fly, but this provides a more efficient implementation: Assuming the already-inverted items are stored in inverse, just return an iterator over them directly.

Providing this default implementation enables external functions, particularly inverted(), to use this optimized implementation when available, instead of having to invert on the fly.

See also bidict.inverted()

Return type:

Iterator[Tuple[VT, KT]]

abstract __iter__()#
abstract __len__()#
__module__ = 'bidict'#
__orig_bases__ = (bidict.BidirectionalMapping[~KT, ~VT], typing.MutableMapping[~KT, ~VT])#
__parameters__ = (~KT, ~VT)#
__reversed__ = None#
abstract __setitem__(key, value)#
__slots__ = ()#
classmethod __subclasshook__(C)#

Abstract classes can override this to customize issubclass().

This is invoked early on by abc.ABCMeta.__subclasscheck__(). It should return True, False or NotImplemented. If it returns NotImplemented, the normal algorithm is used. Otherwise, it overrides the normal algorithm (and the outcome is cached).

clear() None.  Remove all items from D.#
get(k[, d]) D[k] if k in D, else d.  d defaults to None.#
abstract property inverse: BidirectionalMapping[VT, KT]#

The inverse of this bidirectional mapping instance.

See also bidict.BidictBase.inverse, bidict.BidictBase.inv

Raises:

NotImplementedError – Meant to be overridden in subclasses.

items() a set-like object providing a view on D's items#
keys() a set-like object providing a view on D's keys#
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.

popitem() (k, v), remove and return some (key, value) pair#

as a 2-tuple; but raise KeyError if D is empty.

setdefault(k[, d]) D.get(k,d), also set D[k]=d if k not in D#
update([E, ]**F) None.  Update D from mapping/iterable E and F.#

If E present and has a .keys() method, does: for k in E: D[k] = E[k] If E present and lacks .keys() method, does: for (k, v) in E: D[k] = v In either case, this is followed by: for k, v in F.items(): D[k] = v

values() an object providing a view on D's values#
class bidict.BidictBase(*args, **kw)#

Bases: BidirectionalMapping[KT, VT]

Base class implementing BidirectionalMapping.

Parameters:
__abstractmethods__ = frozenset({})#
__annotations__ = {'__reversed__': typing.Any, '_fwdm': typing.MutableMapping[~KT, ~VT], '_fwdm_cls': typing.ClassVar[typing.Type[typing.MutableMapping[typing.Any, typing.Any]]], '_inv_cls': 't.ClassVar[t.Type[BidictBase[t.Any, t.Any]]]', '_invm': typing.MutableMapping[~VT, ~KT], '_invm_cls': typing.ClassVar[typing.Type[typing.MutableMapping[typing.Any, typing.Any]]], '_repr_delegate': typing.ClassVar[typing.Any]}#
__class_getitem__ = <bound method GenericAlias of <class 'bidict.BidictBase'>>#
__contains__(key)[source]#

True if the mapping contains the specified key, else False.

Parameters:

key (Any) –

Return type:

bool

__copy__()#

Make a (shallow) copy of this bidict.

Parameters:

self (BT) –

Return type:

BT

__dict__ = mappingproxy({'__module__': 'bidict', '__annotations__': {'_fwdm': typing.MutableMapping[~KT, ~VT], '_invm': typing.MutableMapping[~VT, ~KT], '_fwdm_cls': typing.ClassVar[typing.Type[typing.MutableMapping[typing.Any, typing.Any]]], '_invm_cls': typing.ClassVar[typing.Type[typing.MutableMapping[typing.Any, typing.Any]]], '_inv_cls': 't.ClassVar[t.Type[BidictBase[t.Any, t.Any]]]', '_repr_delegate': typing.ClassVar[typing.Any], '__reversed__': typing.Any}, '__doc__': 'Base class implementing :class:`BidirectionalMapping`.', 'on_dup': OnDup(key=OD.DROP_OLD, val=OD.RAISE, kv=OD.RAISE), '_fwdm_cls': <class 'dict'>, '_invm_cls': <class 'dict'>, '_repr_delegate': <class 'dict'>, '__init_subclass__': <classmethod(<function BidictBase.__init_subclass__>)>, '_init_class': <classmethod(<function BidictBase._init_class>)>, '_set_reversed': <classmethod(<function BidictBase._set_reversed>)>, '_ensure_inv_cls': <classmethod(<function BidictBase._ensure_inv_cls>)>, '_make_inv_cls': <classmethod(<function BidictBase._make_inv_cls>)>, '_inv_cls_dict_diff': <classmethod(<function BidictBase._inv_cls_dict_diff>)>, '__init__': <function BidictBase.__init__>, 'inverse': <property object>, '_make_inverse': <function BidictBase._make_inverse>, 'inv': <property object>, '__repr__': <function BidictBase.__repr__>, 'values': <function BidictBase.values>, 'keys': <function BidictBase.keys>, 'items': <function BidictBase.items>, '__contains__': <function BidictBase.__contains__>, '__eq__': <function BidictBase.__eq__>, 'equals_order_sensitive': <function BidictBase.equals_order_sensitive>, '_dedup': <function BidictBase._dedup>, '_prep_write': <function BidictBase._prep_write>, '_update': <function BidictBase._update>, 'copy': <function BidictBase.copy>, '_from_other': <staticmethod(<function BidictBase._from_other>)>, '_init_from': <function BidictBase._init_from>, '__copy__': <function BidictBase.copy>, '__or__': <function BidictBase.__or__>, '__ror__': <function BidictBase.__ror__>, '__len__': <function BidictBase.__len__>, '__iter__': <function BidictBase.__iter__>, '__getitem__': <function BidictBase.__getitem__>, '__reduce__': <function BidictBase.__reduce__>, '__orig_bases__': (bidict.BidirectionalMapping[~KT, ~VT],), '__dict__': <attribute '__dict__' of 'BidictBase' objects>, '__weakref__': <attribute '__weakref__' of 'BidictBase' objects>, '__hash__': None, '__parameters__': (~KT, ~VT), '__abstractmethods__': frozenset(), '_abc_impl': <_abc._abc_data object>, '_inv_cls': <class 'bidict.BidictBase'>, '__reversed__': <function _fwdm_reversed>})#
__eq__(other)[source]#

x.__eq__(other) ⟺ x == other

Equivalent to dict(x.items()) == dict(other.items()) but more efficient.

Note that bidict's __eq__() implementation is inherited by subclasses, in particular by the ordered bidict subclasses, so even with ordered bidicts, == comparison is order-insensitive (https://bidict.rtfd.io/other-bidict-types.html#eq-is-order-insensitive).

See also equals_order_sensitive()

Parameters:

other (object) –

Return type:

bool

__getitem__(key)[source]#

x.__getitem__(key) ⟺ x[key]

Parameters:

key (KT) –

Return type:

VT

__hash__ = None#
__init__(*args, **kw)[source]#

Make a new bidirectional mapping. The signature behaves like that of dict. Items passed in are added in the order they are passed, respecting the on_dup class attribute in the process.

Parameters:
Return type:

None

classmethod __init_subclass__()[source]#

This method is called when a class is subclassed.

The default implementation does nothing. It may be overridden to extend subclasses.

Return type:

None

__inverted__()#

Get an iterator over the items in inverse.

This is functionally equivalent to iterating over the items in the forward mapping and inverting each one on the fly, but this provides a more efficient implementation: Assuming the already-inverted items are stored in inverse, just return an iterator over them directly.

Providing this default implementation enables external functions, particularly inverted(), to use this optimized implementation when available, instead of having to invert on the fly.

See also bidict.inverted()

Return type:

Iterator[Tuple[VT, KT]]

__iter__()[source]#

Iterator over the contained keys.

Return type:

Iterator[KT]

__len__()[source]#

The number of contained items.

Return type:

int

__module__ = 'bidict'#
__or__(other)[source]#

Return self|other.

Parameters:
  • self (BT) –

  • other (Mapping[KT, VT]) –

Return type:

BT

__orig_bases__ = (bidict.BidirectionalMapping[~KT, ~VT],)#
__parameters__ = (~KT, ~VT)#
__reduce__()[source]#

Return state information for pickling.

Return type:

Tuple[Any, …]

__repr__()[source]#

See repr().

Return type:

str

__reversed__()#

Iterator over the contained keys in reverse order.

Parameters:

self (BidictBase[KT, Any]) –

Return type:

Iterator[KT]

__ror__(other)[source]#

Return other|self.

Parameters:
  • self (BT) –

  • other (Mapping[KT, VT]) –

Return type:

BT

__slots__ = ()#
classmethod __subclasshook__(C)#

Abstract classes can override this to customize issubclass().

This is invoked early on by abc.ABCMeta.__subclasscheck__(). It should return True, False or NotImplemented. If it returns NotImplemented, the normal algorithm is used. Otherwise, it overrides the normal algorithm (and the outcome is cached).

__weakref__#

list of weak references to the object (if defined)

copy()[source]#

Make a (shallow) copy of this bidict.

Parameters:

self (BT) –

Return type:

BT

equals_order_sensitive(other)[source]#

Order-sensitive equality check.

See also __eq__() is order-insensitive (https://bidict.rtfd.io/other-bidict-types.html#eq-is-order-insensitive)

Parameters:

other (object) –

Return type:

bool

get(k[, d]) D[k] if k in D, else d.  d defaults to None.#
property inv: BidictBase[VT, KT]#

Alias for inverse.

property inverse: BidictBase[VT, KT]#

The inverse of this bidirectional mapping instance.

items()[source]#

A set-like object providing a view on the contained items.

When b._fwdm is a dict, b.items() returns a dict_items object that behaves exactly the same as collections.abc.ItemsView(b), except for:

  • offering better performance

  • being reversible on Python 3.8+

  • having a .mapping attribute in Python 3.10+ that exposes a mappingproxy to b._fwdm.

Return type:

ItemsView[KT, VT]

keys()[source]#

A set-like object providing a view on the contained keys.

When b._fwdm is a dict, b.keys() returns a dict_keys object that behaves exactly the same as collections.abc.KeysView(b), except for

  • offering better performance

  • being reversible on Python 3.8+

  • having a .mapping attribute in Python 3.10+ that exposes a mappingproxy to b._fwdm.

Return type:

KeysView[KT]

on_dup = OnDup(key=OD.DROP_OLD, val=OD.RAISE, kv=OD.RAISE)#
values()[source]#

A set-like object providing a view on the contained values.

Since the values of a bidict are equivalent to the keys of its inverse, this method returns a set-like object for this bidict’s values rather than just a collections.abc.ValuesView. This object supports set operations like union and difference, and constant- rather than linear-time containment checks, and is no more expensive to provide than the less capable collections.abc.ValuesView would be.

See keys() for more information.

Return type:

BidictKeysView[VT]

class bidict.GeneratedBidictInverse#

Bases: object

Base class for dynamically-generated inverse bidict classes.

__dict__ = mappingproxy({'__module__': 'bidict', '__doc__': 'Base class for dynamically-generated inverse bidict classes.', '__dict__': <attribute '__dict__' of 'GeneratedBidictInverse' objects>, '__weakref__': <attribute '__weakref__' of 'GeneratedBidictInverse' objects>, '__annotations__': {}})#
__module__ = 'bidict'#
__weakref__#

list of weak references to the object (if defined)

class bidict.BidictKeysView(mapping)#

Bases: KeysView[KT], ValuesView[KT]

Since the keys of a bidict are the values of its inverse (and vice versa), the ValuesView result of calling bi.values() is also a KeysView of bi.inverse.

__abstractmethods__ = frozenset({})#
__and__(other)#
__annotations__ = {}#
__class_getitem__ = <bound method GenericAlias of <class 'bidict.BidictKeysView'>>#
__contains__(key)#
__dict__ = mappingproxy({'__module__': 'bidict', '__doc__': 'Since the keys of a bidict are the values of its inverse (and vice versa),\n    the :class:`~collections.abc.ValuesView` result of calling *bi.values()*\n    is also a :class:`~collections.abc.KeysView` of *bi.inverse*.\n    ', '__orig_bases__': (typing.KeysView[~KT], typing.ValuesView[~KT]), '__dict__': <attribute '__dict__' of 'BidictKeysView' objects>, '__weakref__': <attribute '__weakref__' of 'BidictKeysView' objects>, '__parameters__': (~KT,), '__abstractmethods__': frozenset(), '_abc_impl': <_abc._abc_data object>, '__annotations__': {}})#
__eq__(other)#

Return self==value.

__ge__(other)#

Return self>=value.

__gt__(other)#

Return self>value.

__hash__ = None#
__init__(mapping)#
classmethod __init_subclass__(*args, **kwargs)#

This method is called when a class is subclassed.

The default implementation does nothing. It may be overridden to extend subclasses.

__iter__()#
__le__(other)#

Return self<=value.

__len__()#
__lt__(other)#

Return self<value.

__module__ = 'bidict'#
__or__(other)#

Return self|value.

__orig_bases__ = (typing.KeysView[~KT], typing.ValuesView[~KT])#
__parameters__ = (~KT,)#
__rand__(other)#
__repr__()#

Return repr(self).

__ror__(other)#

Return value|self.

__rsub__(other)#
__rxor__(other)#
__slots__ = ()#
__sub__(other)#
classmethod __subclasshook__(C)#

Abstract classes can override this to customize issubclass().

This is invoked early on by abc.ABCMeta.__subclasscheck__(). It should return True, False or NotImplemented. If it returns NotImplemented, the normal algorithm is used. Otherwise, it overrides the normal algorithm (and the outcome is cached).

__weakref__#

list of weak references to the object (if defined)

__xor__(other)#
isdisjoint(other)#

Return True if two sets have a null intersection.

class bidict.MutableBidict(*args, **kw)#

Bases: BidictBase[KT, VT], MutableBidirectionalMapping[KT, VT]

Base class for mutable bidirectional mappings.

Parameters:
__abstractmethods__ = frozenset({})#
__annotations__ = {}#
__class_getitem__ = <bound method GenericAlias of <class 'bidict.MutableBidict'>>#
__contains__(key)#

True if the mapping contains the specified key, else False.

Parameters:

key (Any) –

Return type:

bool

__copy__()#

Make a (shallow) copy of this bidict.

Parameters:

self (BT) –

Return type:

BT

__delitem__(key)[source]#

x.__delitem__(y) ⟺ del x[y]

Parameters:

key (KT) –

Return type:

None

__dict__ = mappingproxy({'__module__': 'bidict', '__doc__': 'Base class for mutable bidirectional mappings.', '_pop': <function MutableBidict._pop>, '__delitem__': <function MutableBidict.__delitem__>, '__setitem__': <function MutableBidict.__setitem__>, 'put': <function MutableBidict.put>, 'forceput': <function MutableBidict.forceput>, 'clear': <function MutableBidict.clear>, 'pop': <function MutableBidict.pop>, 'popitem': <function MutableBidict.popitem>, 'update': <function MutableBidict.update>, 'forceupdate': <function MutableBidict.forceupdate>, '__ior__': <function MutableBidict.__ior__>, 'putall': <function MutableBidict.putall>, '__orig_bases__': (bidict.BidictBase[~KT, ~VT], bidict.MutableBidirectionalMapping[~KT, ~VT]), '__parameters__': (~KT, ~VT), '_inv_cls': <class 'bidict.MutableBidict'>, '__reversed__': <function _fwdm_reversed>, '__abstractmethods__': frozenset(), '_abc_impl': <_abc._abc_data object>, '__annotations__': {}})#
__eq__(other)#

x.__eq__(other) ⟺ x == other

Equivalent to dict(x.items()) == dict(other.items()) but more efficient.

Note that bidict's __eq__() implementation is inherited by subclasses, in particular by the ordered bidict subclasses, so even with ordered bidicts, == comparison is order-insensitive (https://bidict.rtfd.io/other-bidict-types.html#eq-is-order-insensitive).

See also equals_order_sensitive()

Parameters:

other (object) –

Return type:

bool

__getitem__(key)#

x.__getitem__(key) ⟺ x[key]

Parameters:

key (KT) –

Return type:

VT

__hash__ = None#
__init__(*args, **kw)#

Make a new bidirectional mapping. The signature behaves like that of dict. Items passed in are added in the order they are passed, respecting the on_dup class attribute in the process.

Parameters:
Return type:

None

classmethod __init_subclass__()#

This method is called when a class is subclassed.

The default implementation does nothing. It may be overridden to extend subclasses.

Return type:

None

__inverted__()#

Get an iterator over the items in inverse.

This is functionally equivalent to iterating over the items in the forward mapping and inverting each one on the fly, but this provides a more efficient implementation: Assuming the already-inverted items are stored in inverse, just return an iterator over them directly.

Providing this default implementation enables external functions, particularly inverted(), to use this optimized implementation when available, instead of having to invert on the fly.

See also bidict.inverted()

Return type:

Iterator[Tuple[VT, KT]]

__ior__(other)[source]#

Return self|=other.

Parameters:

other (Mapping[KT, VT]) –

Return type:

MutableBidict[KT, VT]

__iter__()#

Iterator over the contained keys.

Return type:

Iterator[KT]

__len__()#

The number of contained items.

Return type:

int

__module__ = 'bidict'#
__or__(other)#

Return self|other.

Parameters:
  • self (BT) –

  • other (Mapping[KT, VT]) –

Return type:

BT

__orig_bases__ = (bidict.BidictBase[~KT, ~VT], bidict.MutableBidirectionalMapping[~KT, ~VT])#
__parameters__ = (~KT, ~VT)#
__reduce__()#

Return state information for pickling.

Return type:

Tuple[Any, …]

__repr__()#

See repr().

Return type:

str

__reversed__()#

Iterator over the contained keys in reverse order.

Parameters:

self (BidictBase[KT, Any]) –

Return type:

Iterator[KT]

__ror__(other)#

Return other|self.

Parameters:
  • self (BT) –

  • other (Mapping[KT, VT]) –

Return type:

BT

__setitem__(key, val)[source]#

Set the value for key to val.

If key is already associated with val, this is a no-op.

If key is already associated with a different value, the old value will be replaced with val, as with dict’s __setitem__().

If val is already associated with a different key, an exception is raised to protect against accidental removal of the key that’s currently associated with val.

Use put() instead if you want to specify different behavior in the case that the provided key or value duplicates an existing one. Or use forceput() to unconditionally associate key with val, replacing any existing items as necessary to preserve uniqueness.

Raises:
Parameters:
  • key (KT) –

  • val (VT) –

Return type:

None

__slots__ = ()#
classmethod __subclasshook__(C)#

Abstract classes can override this to customize issubclass().

This is invoked early on by abc.ABCMeta.__subclasscheck__(). It should return True, False or NotImplemented. If it returns NotImplemented, the normal algorithm is used. Otherwise, it overrides the normal algorithm (and the outcome is cached).

__weakref__#

list of weak references to the object (if defined)

clear()[source]#

Remove all items.

Return type:

None

copy()#

Make a (shallow) copy of this bidict.

Parameters:

self (BT) –

Return type:

BT

equals_order_sensitive(other)#

Order-sensitive equality check.

See also __eq__() is order-insensitive (https://bidict.rtfd.io/other-bidict-types.html#eq-is-order-insensitive)

Parameters:

other (object) –

Return type:

bool

forceput(key, val)[source]#

Associate key with val unconditionally.

Replace any existing mappings containing key key or value val as necessary to preserve uniqueness.

Parameters:
  • key (KT) –

  • val (VT) –

Return type:

None

forceupdate(*args, **kw)[source]#

Like a bulk forceput().

Parameters:
Return type:

None

get(k[, d]) D[k] if k in D, else d.  d defaults to None.#
property inv: BidictBase[VT, KT]#

Alias for inverse.

property inverse: BidictBase[VT, KT]#

The inverse of this bidirectional mapping instance.

items()#

A set-like object providing a view on the contained items.

When b._fwdm is a dict, b.items() returns a dict_items object that behaves exactly the same as collections.abc.ItemsView(b), except for:

  • offering better performance

  • being reversible on Python 3.8+

  • having a .mapping attribute in Python 3.10+ that exposes a mappingproxy to b._fwdm.

Return type:

ItemsView[KT, VT]

keys()#

A set-like object providing a view on the contained keys.

When b._fwdm is a dict, b.keys() returns a dict_keys object that behaves exactly the same as collections.abc.KeysView(b), except for

  • offering better performance

  • being reversible on Python 3.8+

  • having a .mapping attribute in Python 3.10+ that exposes a mappingproxy to b._fwdm.

Return type:

KeysView[KT]

on_dup = OnDup(key=OD.DROP_OLD, val=OD.RAISE, kv=OD.RAISE)#
pop(key, default=MissingT.MISSING)[source]#

x.pop(k[, d]) → v

Remove specified key and return the corresponding value.

Raises:

KeyError – if key is not found and no default is provided.

Parameters:
  • key (KT) –

  • default (Union[DT, MissingT]) –

Return type:

Union[VT, DT]

popitem()[source]#

x.popitem() → (k, v)

Remove and return some item as a (key, value) pair.

Raises:

KeyError – if x is empty.

Return type:

Tuple[KT, VT]

put(key, val, on_dup=OnDup(key=OD.RAISE, val=OD.RAISE, kv=OD.RAISE))[source]#

Associate key with val, honoring the OnDup given in on_dup.

For example, if on_dup is ON_DUP_RAISE, then key will be associated with val if and only if key is not already associated with an existing value and val is not already associated with an existing key, otherwise an exception will be raised.

If key is already associated with val, this is a no-op.

Raises:
Parameters:
  • key (KT) –

  • val (VT) –

  • on_dup (OnDup) –

Return type:

None

putall(items, on_dup=OnDup(key=OD.RAISE, val=OD.RAISE, kv=OD.RAISE))[source]#

Like a bulk put().

If one of the given items causes an exception to be raised, none of the items is inserted.

Parameters:
Return type:

None

setdefault(k[, d]) D.get(k,d), also set D[k]=d if k not in D#
update(*args, **kw)[source]#

Like calling putall() with self.on_dup passed for on_dup.

Parameters:
Return type:

None

values()#

A set-like object providing a view on the contained values.

Since the values of a bidict are equivalent to the keys of its inverse, this method returns a set-like object for this bidict’s values rather than just a collections.abc.ValuesView. This object supports set operations like union and difference, and constant- rather than linear-time containment checks, and is no more expensive to provide than the less capable collections.abc.ValuesView would be.

See keys() for more information.

Return type:

BidictKeysView[VT]

class bidict.bidict(*args, **kw)#

Bases: MutableBidict[KT, VT]

The main bidirectional mapping type.

See Introduction and Basic Usage to get started (also available at https://bidict.rtfd.io).

Parameters:
__abstractmethods__ = frozenset({})#
__annotations__ = {}#
__class_getitem__ = <bound method GenericAlias of <class 'bidict.bidict'>>#
__contains__(key)#

True if the mapping contains the specified key, else False.

Parameters:

key (Any) –

Return type:

bool

__copy__()#

Make a (shallow) copy of this bidict.

Parameters:

self (BT) –

Return type:

BT

__delitem__(key)#

x.__delitem__(y) ⟺ del x[y]

Parameters:

key (KT) –

Return type:

None

__dict__ = mappingproxy({'__module__': 'bidict', '__doc__': 'The main bidirectional mapping type.\n\n    See :ref:`intro:Introduction` and :ref:`basic-usage:Basic Usage`\n    to get started (also available at https://bidict.rtfd.io).\n    ', '__orig_bases__': (bidict.MutableBidict[~KT, ~VT],), '__parameters__': (~KT, ~VT), '_inv_cls': <class 'bidict.bidict'>, '__reversed__': <function _fwdm_reversed>, '__abstractmethods__': frozenset(), '_abc_impl': <_abc._abc_data object>, '__annotations__': {}})#
__eq__(other)#

x.__eq__(other) ⟺ x == other

Equivalent to dict(x.items()) == dict(other.items()) but more efficient.

Note that bidict's __eq__() implementation is inherited by subclasses, in particular by the ordered bidict subclasses, so even with ordered bidicts, == comparison is order-insensitive (https://bidict.rtfd.io/other-bidict-types.html#eq-is-order-insensitive).

See also equals_order_sensitive()

Parameters:

other (object) –

Return type:

bool

__getitem__(key)#

x.__getitem__(key) ⟺ x[key]

Parameters:

key (KT) –

Return type:

VT

__hash__ = None#
__init__(*args, **kw)#

Make a new bidirectional mapping. The signature behaves like that of dict. Items passed in are added in the order they are passed, respecting the on_dup class attribute in the process.

Parameters:
Return type:

None

classmethod __init_subclass__()#

This method is called when a class is subclassed.

The default implementation does nothing. It may be overridden to extend subclasses.

Return type:

None

__inverted__()#

Get an iterator over the items in inverse.

This is functionally equivalent to iterating over the items in the forward mapping and inverting each one on the fly, but this provides a more efficient implementation: Assuming the already-inverted items are stored in inverse, just return an iterator over them directly.

Providing this default implementation enables external functions, particularly inverted(), to use this optimized implementation when available, instead of having to invert on the fly.

See also bidict.inverted()

Return type:

Iterator[Tuple[VT, KT]]

__ior__(other)#

Return self|=other.

Parameters:

other (Mapping[KT, VT]) –

Return type:

MutableBidict[KT, VT]

__iter__()#

Iterator over the contained keys.

Return type:

Iterator[KT]

__len__()#

The number of contained items.

Return type:

int

__module__ = 'bidict'#
__or__(other)#

Return self|other.

Parameters:
  • self (BT) –

  • other (Mapping[KT, VT]) –

Return type:

BT

__orig_bases__ = (bidict.MutableBidict[~KT, ~VT],)#
__parameters__ = (~KT, ~VT)#
__reduce__()#

Return state information for pickling.

Return type:

Tuple[Any, …]

__repr__()#

See repr().

Return type:

str

__reversed__()#

Iterator over the contained keys in reverse order.

Parameters:

self (BidictBase[KT, Any]) –

Return type:

Iterator[KT]

__ror__(other)#

Return other|self.

Parameters:
  • self (BT) –

  • other (Mapping[KT, VT]) –

Return type:

BT

__setitem__(key, val)#

Set the value for key to val.

If key is already associated with val, this is a no-op.

If key is already associated with a different value, the old value will be replaced with val, as with dict’s __setitem__().

If val is already associated with a different key, an exception is raised to protect against accidental removal of the key that’s currently associated with val.

Use put() instead if you want to specify different behavior in the case that the provided key or value duplicates an existing one. Or use forceput() to unconditionally associate key with val, replacing any existing items as necessary to preserve uniqueness.

Raises:
Parameters:
  • key (KT) –

  • val (VT) –

Return type:

None

__slots__ = ()#
classmethod __subclasshook__(C)#

Abstract classes can override this to customize issubclass().

This is invoked early on by abc.ABCMeta.__subclasscheck__(). It should return True, False or NotImplemented. If it returns NotImplemented, the normal algorithm is used. Otherwise, it overrides the normal algorithm (and the outcome is cached).

__weakref__#

list of weak references to the object (if defined)

clear()#

Remove all items.

Return type:

None

copy()#

Make a (shallow) copy of this bidict.

Parameters:

self (BT) –

Return type:

BT

equals_order_sensitive(other)#

Order-sensitive equality check.

See also __eq__() is order-insensitive (https://bidict.rtfd.io/other-bidict-types.html#eq-is-order-insensitive)

Parameters:

other (object) –

Return type:

bool

forceput(key, val)#

Associate key with val unconditionally.

Replace any existing mappings containing key key or value val as necessary to preserve uniqueness.

Parameters:
  • key (KT) –

  • val (VT) –

Return type:

None

forceupdate(*args, **kw)#

Like a bulk forceput().

Parameters:
Return type:

None

get(k[, d]) D[k] if k in D, else d.  d defaults to None.#
property inv: BidictBase[VT, KT]#

Alias for inverse.

property inverse: BidictBase[VT, KT]#

The inverse of this bidirectional mapping instance.

items()#

A set-like object providing a view on the contained items.

When b._fwdm is a dict, b.items() returns a dict_items object that behaves exactly the same as collections.abc.ItemsView(b), except for:

  • offering better performance

  • being reversible on Python 3.8+

  • having a .mapping attribute in Python 3.10+ that exposes a mappingproxy to b._fwdm.

Return type:

ItemsView[KT, VT]

keys()#

A set-like object providing a view on the contained keys.

When b._fwdm is a dict, b.keys() returns a dict_keys object that behaves exactly the same as collections.abc.KeysView(b), except for

  • offering better performance

  • being reversible on Python 3.8+

  • having a .mapping attribute in Python 3.10+ that exposes a mappingproxy to b._fwdm.

Return type:

KeysView[KT]

on_dup = OnDup(key=OD.DROP_OLD, val=OD.RAISE, kv=OD.RAISE)#
pop(key, default=MissingT.MISSING)#

x.pop(k[, d]) → v

Remove specified key and return the corresponding value.

Raises:

KeyError – if key is not found and no default is provided.

Parameters:
  • key (KT) –

  • default (Union[DT, MissingT]) –

Return type:

Union[VT, DT]

popitem()#

x.popitem() → (k, v)

Remove and return some item as a (key, value) pair.

Raises:

KeyError – if x is empty.

Return type:

Tuple[KT, VT]

put(key, val, on_dup=OnDup(key=OD.RAISE, val=OD.RAISE, kv=OD.RAISE))#

Associate key with val, honoring the OnDup given in on_dup.

For example, if on_dup is ON_DUP_RAISE, then key will be associated with val if and only if key is not already associated with an existing value and val is not already associated with an existing key, otherwise an exception will be raised.

If key is already associated with val, this is a no-op.

Raises:
Parameters:
  • key (KT) –

  • val (VT) –

  • on_dup (OnDup) –

Return type:

None

putall(items, on_dup=OnDup(key=OD.RAISE, val=OD.RAISE, kv=OD.RAISE))#

Like a bulk put().

If one of the given items causes an exception to be raised, none of the items is inserted.

Parameters:
Return type:

None

setdefault(k[, d]) D.get(k,d), also set D[k]=d if k not in D#
update(*args, **kw)#

Like calling putall() with self.on_dup passed for on_dup.

Parameters:
Return type:

None

values()#

A set-like object providing a view on the contained values.

Since the values of a bidict are equivalent to the keys of its inverse, this method returns a set-like object for this bidict’s values rather than just a collections.abc.ValuesView. This object supports set operations like union and difference, and constant- rather than linear-time containment checks, and is no more expensive to provide than the less capable collections.abc.ValuesView would be.

See keys() for more information.

Return type:

BidictKeysView[VT]

class bidict.frozenbidict(*args, **kw)#

Bases: BidictBase[KT, VT]

Immutable, hashable bidict type.

Parameters:
__abstractmethods__ = frozenset({})#
__annotations__ = {'_hash': <class 'int'>}#
__class_getitem__ = <bound method GenericAlias of <class 'bidict.frozenbidict'>>#
__contains__(key)#

True if the mapping contains the specified key, else False.

Parameters:

key (Any) –

Return type:

bool

__copy__()#

Make a (shallow) copy of this bidict.

Parameters:

self (BT) –

Return type:

BT

__dict__ = mappingproxy({'__module__': 'bidict', '__annotations__': {'_hash': <class 'int'>}, '__doc__': 'Immutable, hashable bidict type.', '__hash__': <function frozenbidict.__hash__>, '__orig_bases__': (bidict.BidictBase[~KT, ~VT],), '__parameters__': (~KT, ~VT), '_inv_cls': <class 'bidict.frozenbidict'>, '__reversed__': <function _fwdm_reversed>, '__abstractmethods__': frozenset(), '_abc_impl': <_abc._abc_data object>})#
__eq__(other)#

x.__eq__(other) ⟺ x == other

Equivalent to dict(x.items()) == dict(other.items()) but more efficient.

Note that bidict's __eq__() implementation is inherited by subclasses, in particular by the ordered bidict subclasses, so even with ordered bidicts, == comparison is order-insensitive (https://bidict.rtfd.io/other-bidict-types.html#eq-is-order-insensitive).

See also equals_order_sensitive()

Parameters:

other (object) –

Return type:

bool

__getitem__(key)#

x.__getitem__(key) ⟺ x[key]

Parameters:

key (KT) –

Return type:

VT

__hash__()[source]#

The hash of this bidict as determined by its items.

Return type:

int

__init__(*args, **kw)#

Make a new bidirectional mapping. The signature behaves like that of dict. Items passed in are added in the order they are passed, respecting the on_dup class attribute in the process.

Parameters:
Return type:

None

classmethod __init_subclass__()#

This method is called when a class is subclassed.

The default implementation does nothing. It may be overridden to extend subclasses.

Return type:

None

__inverted__()#

Get an iterator over the items in inverse.

This is functionally equivalent to iterating over the items in the forward mapping and inverting each one on the fly, but this provides a more efficient implementation: Assuming the already-inverted items are stored in inverse, just return an iterator over them directly.

Providing this default implementation enables external functions, particularly inverted(), to use this optimized implementation when available, instead of having to invert on the fly.

See also bidict.inverted()

Return type:

Iterator[Tuple[VT, KT]]

__iter__()#

Iterator over the contained keys.

Return type:

Iterator[KT]

__len__()#

The number of contained items.

Return type:

int

__module__ = 'bidict'#
__or__(other)#

Return self|other.

Parameters:
  • self (BT) –

  • other (Mapping[KT, VT]) –

Return type:

BT

__orig_bases__ = (bidict.BidictBase[~KT, ~VT],)#
__parameters__ = (~KT, ~VT)#
__reduce__()#

Return state information for pickling.

Return type:

Tuple[Any, …]

__repr__()#

See repr().

Return type:

str

__reversed__()#

Iterator over the contained keys in reverse order.

Parameters:

self (BidictBase[KT, Any]) –

Return type:

Iterator[KT]

__ror__(other)#

Return other|self.

Parameters:
  • self (BT) –

  • other (Mapping[KT, VT]) –

Return type:

BT

__slots__ = ()#
classmethod __subclasshook__(C)#

Abstract classes can override this to customize issubclass().

This is invoked early on by abc.ABCMeta.__subclasscheck__(). It should return True, False or NotImplemented. If it returns NotImplemented, the normal algorithm is used. Otherwise, it overrides the normal algorithm (and the outcome is cached).

__weakref__#

list of weak references to the object (if defined)

copy()#

Make a (shallow) copy of this bidict.

Parameters:

self (BT) –

Return type:

BT

equals_order_sensitive(other)#

Order-sensitive equality check.

See also __eq__() is order-insensitive (https://bidict.rtfd.io/other-bidict-types.html#eq-is-order-insensitive)

Parameters:

other (object) –

Return type:

bool

get(k[, d]) D[k] if k in D, else d.  d defaults to None.#
property inv: BidictBase[VT, KT]#

Alias for inverse.

property inverse: BidictBase[VT, KT]#

The inverse of this bidirectional mapping instance.

items()#

A set-like object providing a view on the contained items.

When b._fwdm is a dict, b.items() returns a dict_items object that behaves exactly the same as collections.abc.ItemsView(b), except for:

  • offering better performance

  • being reversible on Python 3.8+

  • having a .mapping attribute in Python 3.10+ that exposes a mappingproxy to b._fwdm.

Return type:

ItemsView[KT, VT]

keys()#

A set-like object providing a view on the contained keys.

When b._fwdm is a dict, b.keys() returns a dict_keys object that behaves exactly the same as collections.abc.KeysView(b), except for

  • offering better performance

  • being reversible on Python 3.8+

  • having a .mapping attribute in Python 3.10+ that exposes a mappingproxy to b._fwdm.

Return type:

KeysView[KT]

on_dup = OnDup(key=OD.DROP_OLD, val=OD.RAISE, kv=OD.RAISE)#
values()#

A set-like object providing a view on the contained values.

Since the values of a bidict are equivalent to the keys of its inverse, this method returns a set-like object for this bidict’s values rather than just a collections.abc.ValuesView. This object supports set operations like union and difference, and constant- rather than linear-time containment checks, and is no more expensive to provide than the less capable collections.abc.ValuesView would be.

See keys() for more information.

Return type:

BidictKeysView[VT]

class bidict.FrozenOrderedBidict(*args, **kw)#

Bases: OrderedBidictBase[KT, VT]

Hashable, immutable, ordered bidict type.

Like a hashable bidict.OrderedBidict without the mutating APIs, or like a reversible bidict.frozenbidict even on Python < 3.8. (All bidicts are order-preserving when never mutated, so frozenbidict is already order-preserving, but only on Python 3.8+, where dicts are reversible, are all bidicts (including frozenbidict) also reversible.)

If you are using Python 3.8+, frozenbidict gives you everything that FrozenOrderedBidict gives you, but with less space overhead. On the other hand, using FrozenOrderedBidict when you are depending on the ordering of the items can make the ordering dependence more explicit.

Parameters:
__abstractmethods__ = frozenset({})#
__annotations__ = {'__hash__': typing.Callable[[typing.Any], int]}#
__class_getitem__ = <bound method GenericAlias of <class 'bidict.FrozenOrderedBidict'>>#
__contains__(key)#

True if the mapping contains the specified key, else False.

Parameters:

key (Any) –

Return type:

bool

__copy__()#

Make a (shallow) copy of this bidict.

Parameters:

self (BT) –

Return type:

BT

__dict__ = mappingproxy({'__module__': 'bidict', '__annotations__': {'__hash__': typing.Callable[[typing.Any], int]}, '__doc__': 'Hashable, immutable, ordered bidict type.\n\n    Like a hashable :class:`bidict.OrderedBidict`\n    without the mutating APIs, or like a\n    reversible :class:`bidict.frozenbidict` even on Python < 3.8.\n    (All bidicts are order-preserving when never mutated, so frozenbidict is\n    already order-preserving, but only on Python 3.8+, where dicts are\n    reversible, are all bidicts (including frozenbidict) also reversible.)\n\n    If you are using Python 3.8+, frozenbidict gives you everything that\n    FrozenOrderedBidict gives you, but with less space overhead.\n    On the other hand, using FrozenOrderedBidict when you are depending on\n    the ordering of the items can make the ordering dependence more explicit.\n    ', '__hash__': <function frozenbidict.__hash__>, '__orig_bases__': (bidict.OrderedBidictBase[~KT, ~VT],), '__parameters__': (~KT, ~VT), '_inv_cls': <class 'bidict.FrozenOrderedBidict'>, '__abstractmethods__': frozenset(), '_abc_impl': <_abc._abc_data object>})#
__eq__(other)#

x.__eq__(other) ⟺ x == other

Equivalent to dict(x.items()) == dict(other.items()) but more efficient.

Note that bidict's __eq__() implementation is inherited by subclasses, in particular by the ordered bidict subclasses, so even with ordered bidicts, == comparison is order-insensitive (https://bidict.rtfd.io/other-bidict-types.html#eq-is-order-insensitive).

See also equals_order_sensitive()

Parameters:

other (object) –

Return type:

bool

__getitem__(key)#

x.__getitem__(key) ⟺ x[key]

Parameters:

key (KT) –

Return type:

VT

__hash__()#

The hash of this bidict as determined by its items.

Return type:

int

__init__(*args, **kw)#

Make a new ordered bidirectional mapping. The signature behaves like that of dict. Items passed in are added in the order they are passed, respecting the on_dup class attribute in the process.

The order in which items are inserted is remembered, similar to collections.OrderedDict.

Parameters:
Return type:

None

classmethod __init_subclass__()#

This method is called when a class is subclassed.

The default implementation does nothing. It may be overridden to extend subclasses.

Return type:

None

__inverted__()#

Get an iterator over the items in inverse.

This is functionally equivalent to iterating over the items in the forward mapping and inverting each one on the fly, but this provides a more efficient implementation: Assuming the already-inverted items are stored in inverse, just return an iterator over them directly.

Providing this default implementation enables external functions, particularly inverted(), to use this optimized implementation when available, instead of having to invert on the fly.

See also bidict.inverted()

Return type:

Iterator[Tuple[VT, KT]]

__iter__()#

Iterator over the contained keys in insertion order.

Return type:

Iterator[KT]

__len__()#

The number of contained items.

Return type:

int

__module__ = 'bidict'#
__or__(other)#

Return self|other.

Parameters:
  • self (BT) –

  • other (Mapping[KT, VT]) –

Return type:

BT

__orig_bases__ = (bidict.OrderedBidictBase[~KT, ~VT],)#
__parameters__ = (~KT, ~VT)#
__reduce__()#

Return state information for pickling.

Return type:

Tuple[Any, …]

__repr__()#

See repr().

Return type:

str

__reversed__()#

Iterator over the contained keys in reverse insertion order.

Parameters:

self (OrderedBidictBase[KT, VT]) –

Return type:

Iterator[KT]

__ror__(other)#

Return other|self.

Parameters:
  • self (BT) –

  • other (Mapping[KT, VT]) –

Return type:

BT

__slots__ = ()#
classmethod __subclasshook__(C)#

Abstract classes can override this to customize issubclass().

This is invoked early on by abc.ABCMeta.__subclasscheck__(). It should return True, False or NotImplemented. If it returns NotImplemented, the normal algorithm is used. Otherwise, it overrides the normal algorithm (and the outcome is cached).

__weakref__#

list of weak references to the object (if defined)

copy()#

Make a (shallow) copy of this bidict.

Parameters:

self (BT) –

Return type:

BT

equals_order_sensitive(other)#

Order-sensitive equality check.

See also __eq__() is order-insensitive (https://bidict.rtfd.io/other-bidict-types.html#eq-is-order-insensitive)

Parameters:

other (object) –

Return type:

bool

get(k[, d]) D[k] if k in D, else d.  d defaults to None.#
property inv: BidictBase[VT, KT]#

Alias for inverse.

property inverse: BidictBase[VT, KT]#

The inverse of this bidirectional mapping instance.

items()#

A set-like object providing a view on the contained items.

When b._fwdm is a dict, b.items() returns a dict_items object that behaves exactly the same as collections.abc.ItemsView(b), except for:

  • offering better performance

  • being reversible on Python 3.8+

  • having a .mapping attribute in Python 3.10+ that exposes a mappingproxy to b._fwdm.

Return type:

ItemsView[KT, VT]

keys()#

A set-like object providing a view on the contained keys.

When b._fwdm is a dict, b.keys() returns a dict_keys object that behaves exactly the same as collections.abc.KeysView(b), except for

  • offering better performance

  • being reversible on Python 3.8+

  • having a .mapping attribute in Python 3.10+ that exposes a mappingproxy to b._fwdm.

Return type:

KeysView[KT]

on_dup = OnDup(key=OD.DROP_OLD, val=OD.RAISE, kv=OD.RAISE)#
values()#

A set-like object providing a view on the contained values.

Since the values of a bidict are equivalent to the keys of its inverse, this method returns a set-like object for this bidict’s values rather than just a collections.abc.ValuesView. This object supports set operations like union and difference, and constant- rather than linear-time containment checks, and is no more expensive to provide than the less capable collections.abc.ValuesView would be.

See keys() for more information.

Return type:

BidictKeysView[VT]

class bidict.NamedBidictBase#

Bases: object

Base class that namedbidicts derive from.

__dict__ = mappingproxy({'__module__': 'bidict', '__doc__': 'Base class that namedbidicts derive from.', '__dict__': <attribute '__dict__' of 'NamedBidictBase' objects>, '__weakref__': <attribute '__weakref__' of 'NamedBidictBase' objects>, '__annotations__': {}})#
__module__ = 'bidict'#
__weakref__#

list of weak references to the object (if defined)

bidict.namedbidict(typename, keyname, valname, *, base_type=<class 'bidict.bidict'>)#

Create a new subclass of base_type with custom accessors.

Like collections.namedtuple() for bidicts.

The new class’s __name__ and __qualname__ will be set to typename, and its __module__ will be set to the caller’s module.

Instances of the new class will provide access to their inverse instances via the custom keyname_for property, and access to themselves via the custom valname_for property.

See also the namedbidict usage documentation (https://bidict.rtfd.io/other-bidict-types.html#namedbidict)

Raises:
Parameters:
Return type:

Type[BidictBase[KT, VT]]

class bidict.OrderedBidictBase(*args, **kw)#

Bases: BidictBase[KT, VT]

Base class implementing an ordered BidirectionalMapping.

Parameters:
__abstractmethods__ = frozenset({})#
__annotations__ = {'_bykey': <class 'bool'>, '_node_by_korv': bidict.bidict[typing.Any, bidict._orderedbase.Node], '_repr_delegate': typing.ClassVar[typing.Any]}#
__class_getitem__ = <bound method GenericAlias of <class 'bidict.OrderedBidictBase'>>#
__contains__(key)#

True if the mapping contains the specified key, else False.

Parameters:

key (Any) –

Return type:

bool

__copy__()#

Make a (shallow) copy of this bidict.

Parameters:

self (BT) –

Return type:

BT

__dict__ = mappingproxy({'__module__': 'bidict', '__annotations__': {'_repr_delegate': typing.ClassVar[typing.Any], '_node_by_korv': bidict.bidict[typing.Any, bidict._orderedbase.Node], '_bykey': <class 'bool'>}, '__doc__': 'Base class implementing an ordered :class:`BidirectionalMapping`.', '_repr_delegate': <class 'list'>, '__init__': <function OrderedBidictBase.__init__>, '_make_inverse': <function OrderedBidictBase._make_inverse>, '_assoc_node': <function OrderedBidictBase._assoc_node>, '_dissoc_node': <function OrderedBidictBase._dissoc_node>, '_init_from': <function OrderedBidictBase._init_from>, '_prep_write': <function OrderedBidictBase._prep_write>, '__iter__': <function OrderedBidictBase.__iter__>, '__reversed__': <function OrderedBidictBase.__reversed__>, '_iter': <function OrderedBidictBase._iter>, '__orig_bases__': (bidict.BidictBase[~KT, ~VT],), '__parameters__': (~KT, ~VT), '_inv_cls': <class 'bidict.OrderedBidictBase'>, '__abstractmethods__': frozenset(), '_abc_impl': <_abc._abc_data object>})#
__eq__(other)#

x.__eq__(other) ⟺ x == other

Equivalent to dict(x.items()) == dict(other.items()) but more efficient.

Note that bidict's __eq__() implementation is inherited by subclasses, in particular by the ordered bidict subclasses, so even with ordered bidicts, == comparison is order-insensitive (https://bidict.rtfd.io/other-bidict-types.html#eq-is-order-insensitive).

See also equals_order_sensitive()

Parameters:

other (object) –

Return type:

bool

__getitem__(key)#

x.__getitem__(key) ⟺ x[key]

Parameters:

key (KT) –

Return type:

VT

__hash__ = None#
__init__(*args, **kw)[source]#

Make a new ordered bidirectional mapping. The signature behaves like that of dict. Items passed in are added in the order they are passed, respecting the on_dup class attribute in the process.

The order in which items are inserted is remembered, similar to collections.OrderedDict.

Parameters:
Return type:

None

classmethod __init_subclass__()#

This method is called when a class is subclassed.

The default implementation does nothing. It may be overridden to extend subclasses.

Return type:

None

__inverted__()#

Get an iterator over the items in inverse.

This is functionally equivalent to iterating over the items in the forward mapping and inverting each one on the fly, but this provides a more efficient implementation: Assuming the already-inverted items are stored in inverse, just return an iterator over them directly.

Providing this default implementation enables external functions, particularly inverted(), to use this optimized implementation when available, instead of having to invert on the fly.

See also bidict.inverted()

Return type:

Iterator[Tuple[VT, KT]]

__iter__()[source]#

Iterator over the contained keys in insertion order.

Return type:

Iterator[KT]

__len__()#

The number of contained items.

Return type:

int

__module__ = 'bidict'#
__or__(other)#

Return self|other.

Parameters:
  • self (BT) –

  • other (Mapping[KT, VT]) –

Return type:

BT

__orig_bases__ = (bidict.BidictBase[~KT, ~VT],)#
__parameters__ = (~KT, ~VT)#
__reduce__()#

Return state information for pickling.

Return type:

Tuple[Any, …]

__repr__()#

See repr().

Return type:

str

__reversed__()[source]#

Iterator over the contained keys in reverse insertion order.

Parameters:

self (OrderedBidictBase[KT, VT]) –

Return type:

Iterator[KT]

__ror__(other)#

Return other|self.

Parameters:
  • self (BT) –

  • other (Mapping[KT, VT]) –

Return type:

BT

__slots__ = ()#
classmethod __subclasshook__(C)#

Abstract classes can override this to customize issubclass().

This is invoked early on by abc.ABCMeta.__subclasscheck__(). It should return True, False or NotImplemented. If it returns NotImplemented, the normal algorithm is used. Otherwise, it overrides the normal algorithm (and the outcome is cached).

__weakref__#

list of weak references to the object (if defined)

copy()#

Make a (shallow) copy of this bidict.

Parameters:

self (BT) –

Return type:

BT

equals_order_sensitive(other)#

Order-sensitive equality check.

See also __eq__() is order-insensitive (https://bidict.rtfd.io/other-bidict-types.html#eq-is-order-insensitive)

Parameters:

other (object) –

Return type:

bool

get(k[, d]) D[k] if k in D, else d.  d defaults to None.#
property inv: BidictBase[VT, KT]#

Alias for inverse.

property inverse: BidictBase[VT, KT]#

The inverse of this bidirectional mapping instance.

items()#

A set-like object providing a view on the contained items.

When b._fwdm is a dict, b.items() returns a dict_items object that behaves exactly the same as collections.abc.ItemsView(b), except for:

  • offering better performance

  • being reversible on Python 3.8+

  • having a .mapping attribute in Python 3.10+ that exposes a mappingproxy to b._fwdm.

Return type:

ItemsView[KT, VT]

keys()#

A set-like object providing a view on the contained keys.

When b._fwdm is a dict, b.keys() returns a dict_keys object that behaves exactly the same as collections.abc.KeysView(b), except for

  • offering better performance

  • being reversible on Python 3.8+

  • having a .mapping attribute in Python 3.10+ that exposes a mappingproxy to b._fwdm.

Return type:

KeysView[KT]

on_dup = OnDup(key=OD.DROP_OLD, val=OD.RAISE, kv=OD.RAISE)#
values()#

A set-like object providing a view on the contained values.

Since the values of a bidict are equivalent to the keys of its inverse, this method returns a set-like object for this bidict’s values rather than just a collections.abc.ValuesView. This object supports set operations like union and difference, and constant- rather than linear-time containment checks, and is no more expensive to provide than the less capable collections.abc.ValuesView would be.

See keys() for more information.

Return type:

BidictKeysView[VT]

class bidict.OrderedBidict(*args, **kw)#

Bases: OrderedBidictBase[KT, VT], MutableBidict[KT, VT]

Mutable bidict type that maintains items in insertion order.

Parameters:
__abstractmethods__ = frozenset({})#
__annotations__ = {}#
__class_getitem__ = <bound method GenericAlias of <class 'bidict.OrderedBidict'>>#
__contains__(key)#

True if the mapping contains the specified key, else False.

Parameters:

key (Any) –

Return type:

bool

__copy__()#

Make a (shallow) copy of this bidict.

Parameters:

self (BT) –

Return type:

BT

__delitem__(key)#

x.__delitem__(y) ⟺ del x[y]

Parameters:

key (KT) –

Return type:

None

__dict__ = mappingproxy({'__module__': 'bidict', '__doc__': 'Mutable bidict type that maintains items in insertion order.', 'clear': <function OrderedBidict.clear>, '_pop': <function OrderedBidict._pop>, 'popitem': <function OrderedBidict.popitem>, 'move_to_end': <function OrderedBidict.move_to_end>, 'keys': <function OrderedBidict.keys>, 'items': <function OrderedBidict.items>, '__orig_bases__': (bidict.OrderedBidictBase[~KT, ~VT], bidict.MutableBidict[~KT, ~VT]), '__parameters__': (~KT, ~VT), '_inv_cls': <class 'bidict.OrderedBidict'>, '__abstractmethods__': frozenset(), '_abc_impl': <_abc._abc_data object>, '__annotations__': {}})#
__eq__(other)#

x.__eq__(other) ⟺ x == other

Equivalent to dict(x.items()) == dict(other.items()) but more efficient.

Note that bidict's __eq__() implementation is inherited by subclasses, in particular by the ordered bidict subclasses, so even with ordered bidicts, == comparison is order-insensitive (https://bidict.rtfd.io/other-bidict-types.html#eq-is-order-insensitive).

See also equals_order_sensitive()

Parameters:

other (object) –

Return type:

bool

__getitem__(key)#

x.__getitem__(key) ⟺ x[key]

Parameters:

key (KT) –

Return type:

VT

__hash__ = None#
__init__(*args, **kw)#

Make a new ordered bidirectional mapping. The signature behaves like that of dict. Items passed in are added in the order they are passed, respecting the on_dup class attribute in the process.

The order in which items are inserted is remembered, similar to collections.OrderedDict.

Parameters:
Return type:

None

classmethod __init_subclass__()#

This method is called when a class is subclassed.

The default implementation does nothing. It may be overridden to extend subclasses.

Return type:

None

__inverted__()#

Get an iterator over the items in inverse.

This is functionally equivalent to iterating over the items in the forward mapping and inverting each one on the fly, but this provides a more efficient implementation: Assuming the already-inverted items are stored in inverse, just return an iterator over them directly.

Providing this default implementation enables external functions, particularly inverted(), to use this optimized implementation when available, instead of having to invert on the fly.

See also bidict.inverted()

Return type:

Iterator[Tuple[VT, KT]]

__ior__(other)#

Return self|=other.

Parameters:

other (Mapping[KT, VT]) –

Return type:

MutableBidict[KT, VT]

__iter__()#

Iterator over the contained keys in insertion order.

Return type:

Iterator[KT]

__len__()#

The number of contained items.

Return type:

int

__module__ = 'bidict'#
__or__(other)#

Return self|other.

Parameters:
  • self (BT) –

  • other (Mapping[KT, VT]) –

Return type:

BT

__orig_bases__ = (bidict.OrderedBidictBase[~KT, ~VT], bidict.MutableBidict[~KT, ~VT])#
__parameters__ = (~KT, ~VT)#
__reduce__()#

Return state information for pickling.

Return type:

Tuple[Any, …]

__repr__()#

See repr().

Return type:

str

__reversed__()#

Iterator over the contained keys in reverse insertion order.

Parameters:

self (OrderedBidictBase[KT, VT]) –

Return type:

Iterator[KT]

__ror__(other)#

Return other|self.

Parameters:
  • self (BT) –

  • other (Mapping[KT, VT]) –

Return type:

BT

__setitem__(key, val)#

Set the value for key to val.

If key is already associated with val, this is a no-op.

If key is already associated with a different value, the old value will be replaced with val, as with dict’s __setitem__().

If val is already associated with a different key, an exception is raised to protect against accidental removal of the key that’s currently associated with val.

Use put() instead if you want to specify different behavior in the case that the provided key or value duplicates an existing one. Or use forceput() to unconditionally associate key with val, replacing any existing items as necessary to preserve uniqueness.

Raises:
Parameters:
  • key (KT) –

  • val (VT) –

Return type:

None

__slots__ = ()#
classmethod __subclasshook__(C)#

Abstract classes can override this to customize issubclass().

This is invoked early on by abc.ABCMeta.__subclasscheck__(). It should return True, False or NotImplemented. If it returns NotImplemented, the normal algorithm is used. Otherwise, it overrides the normal algorithm (and the outcome is cached).

__weakref__#

list of weak references to the object (if defined)

clear()[source]#

Remove all items.

Return type:

None

copy()#

Make a (shallow) copy of this bidict.

Parameters:

self (BT) –

Return type:

BT

equals_order_sensitive(other)#

Order-sensitive equality check.

See also __eq__() is order-insensitive (https://bidict.rtfd.io/other-bidict-types.html#eq-is-order-insensitive)

Parameters:

other (object) –

Return type:

bool

forceput(key, val)#

Associate key with val unconditionally.

Replace any existing mappings containing key key or value val as necessary to preserve uniqueness.

Parameters:
  • key (KT) –

  • val (VT) –

Return type:

None

forceupdate(*args, **kw)#

Like a bulk forceput().

Parameters:
Return type:

None

get(k[, d]) D[k] if k in D, else d.  d defaults to None.#
property inv: BidictBase[VT, KT]#

Alias for inverse.

property inverse: BidictBase[VT, KT]#

The inverse of this bidirectional mapping instance.

items()[source]#

A set-like object providing a view on the contained items.

Return type:

ItemsView[KT, VT]

keys()[source]#

A set-like object providing a view on the contained keys.

Return type:

KeysView[KT]

move_to_end(key, last=True)[source]#

Move the item with the given key to the end if last is true, else to the beginning.

Raises:

KeyError – if key is missing

Parameters:
  • key (KT) –

  • last (bool) –

Return type:

None

on_dup = OnDup(key=OD.DROP_OLD, val=OD.RAISE, kv=OD.RAISE)#
pop(key, default=MissingT.MISSING)#

x.pop(k[, d]) → v

Remove specified key and return the corresponding value.

Raises:

KeyError – if key is not found and no default is provided.

Parameters:
  • key (KT) –

  • default (Union[DT, MissingT]) –

Return type:

Union[VT, DT]

popitem(last=True)[source]#

b.popitem() → (k, v)

If last is true, remove and return the most recently added item as a (key, value) pair. Otherwise, remove and return the least recently added item.

Raises:

KeyError – if b is empty.

Parameters:

last (bool) –

Return type:

Tuple[KT, VT]

put(key, val, on_dup=OnDup(key=OD.RAISE, val=OD.RAISE, kv=OD.RAISE))#

Associate key with val, honoring the OnDup given in on_dup.

For example, if on_dup is ON_DUP_RAISE, then key will be associated with val if and only if key is not already associated with an existing value and val is not already associated with an existing key, otherwise an exception will be raised.

If key is already associated with val, this is a no-op.

Raises:
Parameters:
  • key (KT) –

  • val (VT) –

  • on_dup (OnDup) –

Return type:

None

putall(items, on_dup=OnDup(key=OD.RAISE, val=OD.RAISE, kv=OD.RAISE))#

Like a bulk put().

If one of the given items causes an exception to be raised, none of the items is inserted.

Parameters:
Return type:

None

setdefault(k[, d]) D.get(k,d), also set D[k]=d if k not in D#
update(*args, **kw)#

Like calling putall() with self.on_dup passed for on_dup.

Parameters:
Return type:

None

values()#

A set-like object providing a view on the contained values.

Since the values of a bidict are equivalent to the keys of its inverse, this method returns a set-like object for this bidict’s values rather than just a collections.abc.ValuesView. This object supports set operations like union and difference, and constant- rather than linear-time containment checks, and is no more expensive to provide than the less capable collections.abc.ValuesView would be.

See keys() for more information.

Return type:

BidictKeysView[VT]

class bidict.OnDup(key=OD.DROP_OLD, val=OD.RAISE, kv=None)#

Bases: _OnDup

A 3-tuple of ODs specifying how to handle the 3 kinds of duplication.

See also Values Must Be Unique (https://bidict.rtfd.io/basic-usage.html#values-must-be-unique)

If kv is not specified, val will be used for kv.

Parameters:
  • key (OD) –

  • val (OD) –

  • kv (OD) –

Return type:

OnDup

__add__(value, /)#

Return self+value.

__annotations__ = {}#
__class_getitem__()#

See PEP 585

__contains__(key, /)#

Return key in self.

__eq__(value, /)#

Return self==value.

__ge__(value, /)#

Return self>=value.

__getattribute__(name, /)#

Return getattr(self, name).

__getitem__(key, /)#

Return self[key].

__getnewargs__()#

Return self as a plain tuple. Used by copy and pickle.

__gt__(value, /)#

Return self>value.

__hash__()#

Return hash(self).

__iter__()#

Implement iter(self).

__le__(value, /)#

Return self<=value.

__len__()#

Return len(self).

__lt__(value, /)#

Return self<value.

__match_args__ = ('key', 'val', 'kv')#
__module__ = 'bidict'#
__mul__(value, /)#

Return self*value.

__ne__(value, /)#

Return self!=value.

static __new__(cls, key=OD.DROP_OLD, val=OD.RAISE, kv=None)[source]#

Override to provide user-friendly default values.

Parameters:
Return type:

OnDup

__repr__()#

Return a nicely formatted representation string

__rmul__(value, /)#

Return value*self.

__slots__ = ()#
count(value, /)#

Return number of occurrences of value.

index(value, start=0, stop=9223372036854775807, /)#

Return first index of value.

Raises ValueError if the value is not present.

key: OD#

Alias for field number 0

kv: OD#

Alias for field number 2

val: OD#

Alias for field number 1

class bidict.OD(value)#

Bases: Enum

An action to take to prevent duplication from occurring.

RAISE = 'RAISE'#
DROP_OLD = 'DROP_OLD'#
DROP_NEW = 'DROP_NEW'#
__module__ = 'bidict'#
exception bidict.BidictException#

Bases: Exception

Base class for bidict exceptions.

__cause__#

exception cause

__context__#

exception context

__delattr__(name, /)#

Implement delattr(self, name).

__dict__ = mappingproxy({'__module__': 'bidict', '__doc__': 'Base class for bidict exceptions.', '__weakref__': <attribute '__weakref__' of 'BidictException' objects>, '__annotations__': {}})#
__getattribute__(name, /)#

Return getattr(self, name).

__init__(*args, **kwargs)#
__module__ = 'bidict'#
__new__(**kwargs)#
__reduce__()#

Helper for pickle.

__repr__()#

Return repr(self).

__setattr__(name, value, /)#

Implement setattr(self, name, value).

__setstate__()#
__str__()#

Return str(self).

__suppress_context__#
__traceback__#
__weakref__#

list of weak references to the object (if defined)

args#
with_traceback()#

Exception.with_traceback(tb) – set self.__traceback__ to tb and return self.

exception bidict.DuplicationError#

Bases: BidictException

Base class for exceptions raised when uniqueness is violated as per the :attr:~bidict.RAISE` OnDupAction.

__annotations__ = {}#
__cause__#

exception cause

__context__#

exception context

__delattr__(name, /)#

Implement delattr(self, name).

__dict__ = mappingproxy({'__module__': 'bidict', '__doc__': 'Base class for exceptions raised when uniqueness is violated\n    as per the :attr:~bidict.RAISE` :class:`~bidict.OnDupAction`.\n    ', '__annotations__': {}})#
__getattribute__(name, /)#

Return getattr(self, name).

__init__(*args, **kwargs)#
__module__ = 'bidict'#
__new__(**kwargs)#
__reduce__()#

Helper for pickle.

__repr__()#

Return repr(self).

__setattr__(name, value, /)#

Implement setattr(self, name, value).

__setstate__()#
__str__()#

Return str(self).

__suppress_context__#
__traceback__#
__weakref__#

list of weak references to the object (if defined)

args#
with_traceback()#

Exception.with_traceback(tb) – set self.__traceback__ to tb and return self.

exception bidict.KeyDuplicationError#

Bases: DuplicationError

Raised when a given key is not unique.

__annotations__ = {}#
__cause__#

exception cause

__context__#

exception context

__delattr__(name, /)#

Implement delattr(self, name).

__dict__ = mappingproxy({'__module__': 'bidict', '__doc__': 'Raised when a given key is not unique.', '__annotations__': {}})#
__getattribute__(name, /)#

Return getattr(self, name).

__init__(*args, **kwargs)#
__module__ = 'bidict'#
__new__(**kwargs)#
__reduce__()#

Helper for pickle.

__repr__()#

Return repr(self).

__setattr__(name, value, /)#

Implement setattr(self, name, value).

__setstate__()#
__str__()#

Return str(self).

__suppress_context__#
__traceback__#
__weakref__#

list of weak references to the object (if defined)

args#
with_traceback()#

Exception.with_traceback(tb) – set self.__traceback__ to tb and return self.

exception bidict.ValueDuplicationError#

Bases: DuplicationError

Raised when a given value is not unique.

__annotations__ = {}#
__cause__#

exception cause

__context__#

exception context

__delattr__(name, /)#

Implement delattr(self, name).

__dict__ = mappingproxy({'__module__': 'bidict', '__doc__': 'Raised when a given value is not unique.', '__annotations__': {}})#
__getattribute__(name, /)#

Return getattr(self, name).

__init__(*args, **kwargs)#
__module__ = 'bidict'#
__new__(**kwargs)#
__reduce__()#

Helper for pickle.

__repr__()#

Return repr(self).

__setattr__(name, value, /)#

Implement setattr(self, name, value).

__setstate__()#
__str__()#

Return str(self).

__suppress_context__#
__traceback__#
__weakref__#

list of weak references to the object (if defined)

args#
with_traceback()#

Exception.with_traceback(tb) – set self.__traceback__ to tb and return self.

exception bidict.KeyAndValueDuplicationError#

Bases: KeyDuplicationError, ValueDuplicationError

Raised when a given item’s key and value are not unique.

That is, its key duplicates that of another item, and its value duplicates that of a different other item.

__annotations__ = {}#
__cause__#

exception cause

__context__#

exception context

__delattr__(name, /)#

Implement delattr(self, name).

__dict__ = mappingproxy({'__module__': 'bidict', '__doc__': "Raised when a given item's key and value are not unique.\n\n    That is, its key duplicates that of another item,\n    and its value duplicates that of a different other item.\n    ", '__annotations__': {}})#
__getattribute__(name, /)#

Return getattr(self, name).

__init__(*args, **kwargs)#
__module__ = 'bidict'#
__new__(**kwargs)#
__reduce__()#

Helper for pickle.

__repr__()#

Return repr(self).

__setattr__(name, value, /)#

Implement setattr(self, name, value).

__setstate__()#
__str__()#

Return str(self).

__suppress_context__#
__traceback__#
__weakref__#

list of weak references to the object (if defined)

args#
with_traceback()#

Exception.with_traceback(tb) – set self.__traceback__ to tb and return self.

bidict.inverted(arg)#

Yield the inverse items of the provided object.

If arg has a callable() __inverted__ attribute, return the result of calling it.

Otherwise, return an iterator over the items in arg, inverting each item on the fly.

See also bidict.BidirectionalMapping.__inverted__

Parameters:

arg (Union[Mapping[KT, VT], Iterable[Tuple[KT, VT]]]) –

Return type:

Iterable[Tuple[VT, KT]]

bidict.OnDupAction#

Alias

bidict.RAISE = OD.RAISE#

An action to take to prevent duplication from occurring.

bidict.DROP_OLD = OD.DROP_OLD#

An action to take to prevent duplication from occurring.

bidict.DROP_NEW = OD.DROP_NEW#

An action to take to prevent duplication from occurring.

bidict.ON_DUP_DEFAULT = OnDup(key=OD.DROP_OLD, val=OD.RAISE, kv=OD.RAISE)#

A 3-tuple of ODs specifying how to handle the 3 kinds of duplication.

See also Values Must Be Unique (https://bidict.rtfd.io/basic-usage.html#values-must-be-unique)

If kv is not specified, val will be used for kv.

bidict.ON_DUP_RAISE = OnDup(key=OD.RAISE, val=OD.RAISE, kv=OD.RAISE)#

A 3-tuple of ODs specifying how to handle the 3 kinds of duplication.

See also Values Must Be Unique (https://bidict.rtfd.io/basic-usage.html#values-must-be-unique)

If kv is not specified, val will be used for kv.

bidict.ON_DUP_DROP_OLD = OnDup(key=OD.DROP_OLD, val=OD.DROP_OLD, kv=OD.DROP_OLD)#

A 3-tuple of ODs specifying how to handle the 3 kinds of duplication.

See also Values Must Be Unique (https://bidict.rtfd.io/basic-usage.html#values-must-be-unique)

If kv is not specified, val will be used for kv.

bidict.__version__#

The version of bidict represented as a string.