The namedlist package in Python is similar to collections.namedtuple and allows for mutable instances.
Declaring mutable default values requires the use of FACTORY, ex:
from namedlist import namedlist, FACTORYA = namedlist('A', [('x', FACTORY(list))])I now need to that list to have defaults, but the code below doesn't work:
A = namedlist('A', [('x', FACTORY(list([1, 2])))])The code below creates a list with defaults, but every instance of A will point to the same object, which is the reason we need factories in the first place:
A = namedlist('A', [('x', [1, 2])])How do I create a namedlist field with a factory with values?
Best Answer
You need to provide a function to FACTORY that creates a new object when called.
A = namedlist('A', [('x', FACTORY(lambda: [1, 2]))])