As of now, @private and @class_modifier allow users outside of the scope to access class variables, class methods, and static methods. This is because we can't hook on to type, without some black magic at least. So, let's add the black magic!

We can only have one function wrapped to type.getattribute, so we need some sort of global storage for all types decorated with supports_private. Then, we can use ctypes (or alternatively, a C extension, but then we have to bring cibuildwheel into the build step) to modify the object structure and set tp_getattr. Finally, we need to call PyType_Ready (or PyType_Modified, I can't remember).

Putting @supports_private on every class might get tedious for some users. privates.py could add an inject call or something similar that goes through the global scope (via get_back_frame().f_globals) and calls supports_privates on each type. This shouldn't apply to built-in types though (such as str). An example would look like:

from privates import inject

inject()

# No @supports_privates is needed!
class Foo:
    __readonly__ = "bar",

    def __init__(self) -> None:
        self.bar = "hello world"