Mockup

class Activity:
    def __init__(self, _id, name):
        self.id = _id
        self.name = name
        self.list_of_activities = []

    def get_activities(self):
        self.list_of_activities = [] #reset the list anytime the method is called

        '''the method then gets the input from the gui (pyside)
        creates different Activity objects and appends them to the list'''

        #i feel it's better to return the list instead of storing it internally'

    def other_method(self):
        pass # should list_activities passed to it but i just use self.list_of_activities instead there are several methods like this