I would like to be able to accumulate values of accessed variables into a list of that object. I was thinking of using Enum for it, as one of my requirement is to be able to use code completion in PyCharm and with Enum something like Keys.KEY_A.KEY_B in PyCharm always gives all the options of class Keys as code completion.
My expected behaviour is like this:
# define some class which holds all the possible values
class Keys(Enum):
KEY_A = "a"
KEY_B = "b"
F4 = "f4"
if __name__ == "__main__":
# when attribute is accessed, its value is stored internally in some list
k1 = Keys().KEY_A.KEY_B
print(k1.items())
# ["a", "b"]
k1.F4
print(k1.items())
# ["a", "b", "f4"]
# when object is instantiated the list is empty
k2 = Keys().KEY_A.F4
print(k2.items())
# ["a", "f4"]
The best solution I was able to do was
def cumulative_decorator(item):
class cumul_property:
def __init__(self, func):
self.__doc__ = getattr(func, "__doc__")
self.func = func
def __get__(self, instance, owner):
if not instance._items:
return type(instance)(item)
instance._items.append(item)
return instance
return cumul_property
class Cumulative:
def __init__(key: str = None):
self._items = [key] if key else []
@cumulative_decorator(Keys.KEY_A)
def KEY_A(self) -> "Cumulative":
return self
But to implement every value as a property is "too wordy", and also code completion doesn't work correctly when made I parent class that implements basic behaviour, so that I can inherit from it and use this funcionality not only for Keys but also other classes. I was hoping to just implement one or two additional methods in the class Keys and solve this problem, but as Enum is returning the same class for the same value if I added any internal list, it just accumulated more and more with every access.
I'm looking for an advice how I could implement my "expected behaviour".