'''Demonstrate that the Counter fast-path still calls
   hash twice per element (one on the getitem and again
   for the setitem).

'''

from collections import Counter

class HT(tuple):
    
    def __hash__(self):
        print('{hash: %r}' % self)
        return tuple.__hash__(self)
    
    def __eq__(self, other):
        print('{%r == %r}' % (self, other))
        return tuple.__eq__(self, other)

class HI(int):
    
    def __hash__(self):
        print('[hash: %r]' % self)
        return int.__hash__(self)
    
    def __eq__(self, other):
        print('[%r == %r]' % (self, other))
        return int.__eq__(self, other)
    

if __name__ == '__main__':

    n = 6
    data = [HT((HI(i),)) for i in (list(range(n)) + list(range(n)))]
    Counter(data)