relentless.collections.FixedKeyDict#

class relentless.collections.FixedKeyDict(keys, default=None)#

Dictionary with fixed keys.

Parameters:

keys (array_like) – List of keys to be fixed.
default (scalar) – Initial value to fill in the dictionary, defaults to None.

Examples

Create a keyed dictionary:

d = FixedKeyDict(keys=('A','B'))

Default values:

>>> print(d)
{'A': None, 'B': None}

Set default values:

d = FixedKeyDict(keys=('A','B'), default=0.0)
>>> print(d)
{'A':0.0, 'B':0.0}

Iterate as a dictionary:

for k in d:
    d[k] = 1.0

Access by key:

>>> d['A']
1.0
>>> d['B']
1.0

Partially reassign/update values:

d.update({'A':0.5})
d.update(A=0.5)  # equivalent statement
>>> print(d)
{'A':0.5, 'B':1.0}

Single-key dictionary still needs keys as a tuple:

FixedKeyDict(keys=('A',))

Methods

`clear`()	Clear entries in the dictionary, resetting to default.
`get`(k[,d])
`items`()
`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`()

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.

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