ihoop

Strict, immutable Abstract/Final classes

Do you like python, but wish it is was more like Julia? Do like Julia, but wish it was a language other people used? Did you read Design Patterns: Elements of Reusable Object-Oriented Software, but wish you didn't?

Meet ihoop: a tiny library that turns plain Python classes into frozen, Abstract/Final instances. Drop in Strict as a base class and get:

• Immutability by default: once __init__ finishes, your objects are read-only.
• Abstract or Final:
  • Abstract classes: can be subclassed, but cannot be instantiated.
  • Concrete classes: can be instantiated, but cannot be subclassed.
    -Abstract attributes, not just methods: Declare with AbstractAttribute[T]; subclasses must supply (via type hints) a real value.
• No dependencies: Pure Python.

This package was largely copied inspired by equinox's strict=True flag. For more information see https://docs.kidger.site/equinox/pattern/.

Why is it called ihoop? Because (i) (h)ate (o)bject (o)riented (p)rogramming 😉

Example

from ihoop import Strict, AbstractAttribute


class AbstractAnimal(Strict):
    name: AbstractAttribute[str]


class Dog(AbstractAnimal):
    name: str

    def __init__(self, name: str):
        self.name = name


>>> Dog("Fido").name
'Fido'
>>> d = Dog("Rex")
>>> d.name = "Max"
AttributeError: Cannot set attribute 'name' on frozen instance of Dog. strict objects are immutable after initialization.

Roadmap

• abstractclassvar: strictness for class variables.
• dataclass testing and integration