| f | from collections import Counter | f | from collections import Counter | 
            |  |  |  |  | 
            |  | class DefCounter(Counter): |  | class DefCounter(Counter): | 
            |  |  |  |  | 
            |  | def __init__(self, iterable=None, **kwargs): |  | def __init__(self, iterable=None, **kwargs): | 
            | n | self.missing_value = kwargs.pop('missing', -1) | n | self.missing = kwargs.pop('missing', -1) | 
            |  | super().__init__(iterable, **kwargs) |  | super().__init__(iterable, **kwargs) | 
            |  |  |  |  | 
            |  | def __missing__(self, key): |  | def __missing__(self, key): | 
            | t | return self.missing_value | t | return self.missing | 
            |  |  |  |  | 
            |  | def __abs__(self): |  | def __abs__(self): | 
            |  | return sum((value for value in self.values() if value > 0)) |  | return sum((value for value in self.values() if value > 0)) |