| f | def sizer(cls): | f | def sizer(cls): | 
            |  |  |  |  | 
            | n | def get_size(self): | n | def calculate_size(instance): | 
            |  | if hasattr(self, '_custom_size'): |  | if hasattr(instance, '_custom_size'): | 
            |  | return self._custom_size |  | return instance._custom_size | 
            |  | if hasattr(self, '__len__'): |  | if hasattr(instance, '__len__'): | 
            |  | return len(self) |  | return len(instance) | 
            |  | elif hasattr(self, '__abs__'): |  | if hasattr(instance, '__abs__'): | 
            |  | return abs(self) |  | return abs(instance) | 
            |  | else: |  |  | 
            |  | return 0 |  | return 0 | 
            |  |  |  |  | 
            | n | def set_size(self, val): | n | def set_custom_size(instance, value): | 
            |  | self._custom_size = val |  | instance._custom_size = value | 
            |  |  |  |  | 
            | t | def del_size(self): | t | def delete_custom_size(instance): | 
            |  | if hasattr(self, '_custom_size'): |  | if hasattr(instance, '_custom_size'): | 
            |  | del self._custom_size |  | del instance._custom_size | 
            |  | cls.size = property(get_size, set_size, del_size) |  | cls.size = property(calculate_size, set_custom_size, delete_custom_s | 
            |  |  |  | ize) | 
            |  | return cls |  | return cls |