FrozenDefaultDict

class tqec.plaquette.FrozenDefaultDict(arg=None, *, default_factory=None)

Bases: Generic[K, V], Mapping[K, V]

A defaultdict implementation that cannot be mutated.

This class re-defines all the mutating methods of defaultdict (i.e., all the mutating methods of dict and __missing__) in order to make any instance immutable.

Note on re-defining __missing__:

The standard defaultdict implementation is entirely based on the __missing__ method (described here https://docs.python.org/3/library/collections.html#collections.defaultdict.__missing__) that is called when a user-provided key was not found in the defined keys. This __missing__ method try to use self.default_factory to create a new value and inserts that new value in the dictionary. That last part is problematic for Plaquettes and in particular to compare collections of Plaquettes through __hash__ and __eq__.

Methods

__init__([arg, default_factory])
get(k[,d])
has_default_factory()
items()
keys()
map_keys(callable)
map_values(callable)
values()

Attributes

default_factory

Detailed methods

Parameters:

• arg (Mapping[K, V] | Iterable[tuple[K, V]] | None)

• default_factory (Callable[[], V] | None)

__init__(arg=None, *, default_factory=None)

Parameters:

• arg (Mapping[K, V] | Iterable[tuple[K, V]] | None)

• default_factory (Callable[[], V] | None)

Return type:

None

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

has_default_factory()

Return type:

bool

items() → a set-like object providing a view on D's items

keys() → a set-like object providing a view on D's keys

map_keys(callable)

Parameters:

callable (Callable[[K], K])

Return type:

FrozenDefaultDict[K, V]

map_values(callable)

Parameters:

callable (Callable[[V], Vp])

Return type:

FrozenDefaultDict[K, Vp]

values() → an object providing a view on D's values