BiMap

class hugr.utils.BiMap(fwd: Mapping[L, R] | None = None)

Bases: MutableMapping, Generic[L, R]

Bidirectional map backed by two dictionaries, between left types L and right types R.

Methods

clear
delete_left	Delete a left key and its right value.
delete_right	Delete a right key and its left value.
get
get_left	Get a left value using a right key.
get_right	Get a right value using a left key.
insert_left	Insert a left key and right value.
insert_right	Insert a right key and left value.
items	Iterator over left, right pairs.
keys
pop	If key is not found, d is returned if given, otherwise KeyError is raised.
popitem	as a 2-tuple; but raise KeyError if D is empty.
setdefault
update	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

Attributes

fwd
bck

clear() → None.  Remove all items from D.

delete_left(key: L) → None

Delete a left key and its right value.

Parameters:

key – Left key.

Raises:

KeyError – If the key is not found.

Example

>>> bm = BiMap({"a": 1})
>>> bm.delete_left("a")
>>> bm
BiMap({})

delete_right(key: R) → None

Delete a right key and its left value.

Parameters:

key – Right key.

Raises:

KeyError – If the key is not found.

Example

>>> bm = BiMap({"a": 1})
>>> bm.delete_right(1)
>>> bm
BiMap({})

get(k[, d]) → D[k] if k in D, else d.  d defaults to None.

get_left(key: R) → L | None

Get a left value using a right key.

Example

>>> bm = BiMap({"a": 1})
>>> bm.get_left(1)
'a'
>>> bm.get_left(2)

get_right(key: L) → R | None

Get a right value using a left key.

Example

>>> bm = BiMap({"a": 1})
>>> bm.get_right("a")
1
>>> bm.get_right("b")

insert_left(key: L, value: R) → None

Insert a left key and right value. If the key or value already exist, the existing key-value pair is replaced.

Parameters:

• key – Left key.

• value – Right value.

Example

>>> bm = BiMap()
>>> bm.insert_left("a", 1)
>>> bm["a"]
1

insert_right(key: R, value: L) → None

Insert a right key and left value. If the key or value already exist, the existing key-value pair is replaced.

Parameters:

• key – Right key.

• value – Left value.

Example

>>> bm = BiMap()
>>> bm.insert_right(1, "a")
>>> bm["a"]
1

items() → ItemsView[L, R]

Iterator over left, right pairs.

Example

>>> bm = BiMap({"a": 1, "b": 2})
>>> list(bm.items())
[('a', 1), ('b', 2)]

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