Base Classes¶

About¶

FrozenBase is the base class for frozendict and FrozenOrderedDict. If you wish to construct your own frozen dictionary classes, you may inherit from this class.

API Reference¶

Base Classes

Classes:

`DictWrapper`(args, *kwds)	Abstract Mixin class for classes that wrap a dict object or similar
`FrozenBase`(args, *kwds)	Abstract Base Class for Frozen dictionaries
`MutableBase`(args, *kwds)	Abstract Base Class for mutable dictionaries

class DictWrapper(*args, **kwds)[source]¶

Bases: collections.abc.Mapping, typing.Generic

Abstract Mixin class for classes that wrap a dict object or similar

Methods:

`__contains__`(key)	Return `key in self`.
`__eq__`(other)	Return `self == other`.
`__getitem__`(key)	Return `self[key]`.
`__iter__`()	Iterates over the dictionary’s keys
`__len__`()	Returns the number of keys in the dictionary.
`__repr__`()	Return a string representation of the `DictWrapper`.
`get`()	Return the value for `k` if `k` is in the dictionary, else `default`.
`items`()	Returns a set-like object providing a view on the `bdict`’s items.
`keys`()	Returns a set-like object providing a view on the `bdict`’s keys.
`values`()	Returns an object providing a view on the `bdict`’s values.

__contains__(key)[source]¶

Return key in self.

Parameters: key (object)
Return type: bool

__eq__(other)¶

Return self == other.

Return type: bool

__getitem__(key)[source]¶

Return self[key].

Parameters: key (~KT)
Return type: ~VT

__iter__()[source]¶

Iterates over the dictionary’s keys

Return type: Iterator[~KT]

__len__()[source]¶

Returns the number of keys in the dictionary.

Return type: int

__repr__()[source]¶

Return a string representation of the DictWrapper.

Return type: str

get(k: KT) → Optional[VT][source]¶

get(k: KT, default: Union[VT, T]) → Union[VT, T]

Return the value for k if k is in the dictionary, else default.

Parameters

k – The key to return the value for.
default – The value to return if key is not in the dictionary. Default None.

items()[source]¶

Returns a set-like object providing a view on the bdict’s items.

Return type: AbstractSet[Tuple[~KT, ~VT]]

keys()[source]¶

Returns a set-like object providing a view on the bdict’s keys.

Return type: AbstractSet[~KT]

values()[source]¶

Returns an object providing a view on the bdict’s values.

Return type: ValuesView[~VT]

class FrozenBase(*args, **kwds)[source]¶

Bases: cawdrey.base.DictWrapper

Abstract Base Class for Frozen dictionaries

Used by frozendict and FrozenOrderedDict.

Custom subclasses must implement at a minimum __init__, copy, fromkeys.

Methods:

`__contains__`(key)	Return `key in self`.
`__eq__`(other)	Return `self == other`.
`__getitem__`(key)	Return `self[key]`.
`__iter__`()	Iterates over the dictionary’s keys
`__len__`()	Returns the number of keys in the dictionary.
`__repr__`()	Return a string representation of the `DictWrapper`.
`fromkeys`()	Create a new dictionary with keys from iterable and values set to value.
`get`(k[, default])	Return the value for `k` if `k` is in the dictionary, else `default`.
`items`()	Returns a set-like object providing a view on the `bdict`’s items.
`keys`()	Returns a set-like object providing a view on the `bdict`’s keys.
`values`()	Returns an object providing a view on the `bdict`’s values.

__contains__(key)¶

Return key in self.

Parameters: key (object)
Return type: bool

__eq__(other)¶

Return self == other.

Return type: bool

__getitem__(key)¶

Return self[key].

Parameters: key (~KT)
Return type: ~VT

__iter__()¶

Iterates over the dictionary’s keys

Return type: Iterator[~KT]

__len__()¶

Returns the number of keys in the dictionary.

Return type: int

__repr__()¶

Return a string representation of the DictWrapper.

Return type: str

classmethod fromkeys(iterable: Iterable[_T]) → FrozenBase[_T, Any][source]¶
classmethod fromkeys(iterable: Iterable[_T], value: _S) → FrozenBase[_T, _S]: Create a new dictionary with keys from iterable and values set to value.

get(k, default=None)¶

Return the value for k if k is in the dictionary, else default.

Parameters

k – The key to return the value for.
default – The value to return if key is not in the dictionary. Default None.

items()¶

Returns a set-like object providing a view on the bdict’s items.

Return type: AbstractSet[Tuple[~KT, ~VT]]

keys()¶

Returns a set-like object providing a view on the bdict’s keys.

Return type: AbstractSet[~KT]

values()¶

Returns an object providing a view on the bdict’s values.

Return type: ValuesView[~VT]

class MutableBase(*args, **kwds)[source]¶

Bases: cawdrey.base.DictWrapper, collections.abc.MutableMapping, typing.Generic

Abstract Base Class for mutable dictionaries

Used by NonelessDict and NonelessOrderedDict.

Custom subclasses must implement at a minimum __init__, copy, fromkeys.

Methods:

`__contains__`(key)	Return `key in self`.
`__eq__`(other)	Return `self == other`.
`__getitem__`(key)	Return `self[key]`.
`__iter__`()	Iterates over the dictionary’s keys
`__len__`()	Returns the number of keys in the dictionary.
`__repr__`()	Return a string representation of the `DictWrapper`.
`clear`()
`fromkeys`()	Create a new dictionary with keys from iterable and values set to value.
`get`(k[, default])	Return the value for `k` if `k` is in the dictionary, else `default`.
`items`()	Returns a set-like object providing a view on the `bdict`’s items.
`keys`()	Returns a set-like object providing a view on the `bdict`’s keys.
`pop`(k[,d])	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`(k[,d])
`update`([E, ]**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`()	Returns an object providing a view on the `bdict`’s values.

__contains__(key)¶

Return key in self.

Parameters: key (object)
Return type: bool

__eq__(other)¶

Return self == other.

Return type: bool

__getitem__(key)¶

Return self[key].

Parameters: key (~KT)
Return type: ~VT

__iter__()¶

Iterates over the dictionary’s keys

Return type: Iterator[~KT]

__len__()¶

Returns the number of keys in the dictionary.

Return type: int

__repr__()¶

Return a string representation of the DictWrapper.

Return type: str

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

classmethod fromkeys(iterable: Iterable[_T]) → MutableBase[_T, Any][source]¶
classmethod fromkeys(iterable: Iterable[_T], value: _S) → MutableBase[_T, _S]: Create a new dictionary with keys from iterable and values set to value.

get(k, default=None)¶

Return the value for k if k is in the dictionary, else default.

Parameters

k – The key to return the value for.
default – The value to return if key is not in the dictionary. Default None.

items()¶

Returns a set-like object providing a view on the bdict’s items.

Return type: AbstractSet[Tuple[~KT, ~VT]]

keys()¶

Returns a set-like object providing a view on the bdict’s keys.

Return type: AbstractSet[~KT]

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()¶

Returns an object providing a view on the bdict’s values.

Return type: ValuesView[~VT]