count disordered pairs in array code example

Example 1: numpy count the number of 1s in array

a = numpy.array([0, 3, 0, 1, 0, 1, 2, 1, 0, 0, 0, 0, 1, 3, 4])
unique, counts = numpy.unique(a, return_counts=True)
dict(zip(unique, counts))
{0: 7, 1: 4, 2: 1, 3: 2, 4: 1}

Example 2: defaultdict count key value pairs

d = {'a': 1, 'b': 1, 'c': 3, 'd': 4}
>>> sum(d.values())