1class Slot:
 2    def __init__(self, object_limit=None, size_limit=None):
 3        self.object_limit = object_limit
 4        self.size_limit = size_limit
 5
 6    def __set_name__(self, owner, name):
 7        self.name = name
 8
 9    def check(self, instance):
10        if self.name not in instance.__dict__:
11            instance.__dict__[self.name] = []
12        return instance.__dict__[self.name]
13
14    def __get__(self, instance, owner):
15        if instance is None:
16            return self
17        return tuple(self.check(instance))
18
19    def __set__(self, instance, value):
20        storage = self.check(instance)
21
22        if self.object_limit is not None:
23            if len(storage) + 1 > self.object_limit:
24                raise ValueError("Object limit exceeded")
25
26        if self.size_limit is not None:
27            total = 0
28            for x in storage:
29                total += len(x)
30
31            if total + len(value) > self.size_limit:
32                raise ValueError("Size limit exceeded")
33
34        storage.append(value)
35
36    def __delete__(self, instance):
37        storage = self.check(instance)
38
39        if len(storage) > 0:
40            del storage[0]