跨脚本共享类变量吗？

Question

I'm working on a set of Python projects with a lot of shared back-end functionality. To avoid code duplication, I've put this shared functionality into modules.

One such module is an event system. I want the event system to be global across a single project, so I defined an EventDispatcher class with class-level variables and methods:

event_name = str
event_data = Any
listener_callback = Callable[[event_name, event_data], None]

class EventDispatcher:
    # event name, List<event_callback>
    _listeners: Dict[event_name, Set[listener_callback]] = {}

    @classmethod
    def register_listener(cls, event: event_name, listener: listener_callback) -> None:
        # get the existing list of listeners for this event and append the new listener to it
        listener_callbacks: Set[listener_callback] = cls._listeners.get(event, set())
        listener_callbacks.add(listener)

        # put the listener list back in the map
        cls._listeners[event] = listener_callbacks

    #other listener methods follow

Because everything is class-level, I should be able to call EventDispatcher.register_listener in any class in my project, and all of the registered listeners should be added to the same list.

My concern is the other projects. Because of the amount of shared functionality, I'm running all projects from the same virtual environment. Will this cause EventDispatcher and co. to be shared across all code in the virtual environment, so events registered in one project can be fired from another, or will each project get its own copy?

As a followup question, if the shared virtual environment does cause EventDispatcher 's class variable to be shared across every project in the virtual environment, will giving each project a separate virtual environment produce the behavior I actually want?

Answer 1

No. As long as your programs are in different files and you aren't importing a file containing the EventDispatcher class, it will not be shared in any way.

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A virtual environment will only share python version and installed packages.