python numpy ユークリッド距離

>>> a
[1, 2, 3]
>>> b
[4, 5, 6]
>>> A = numpy.array(a)
>>> B = numpy.array(b)
>>> d2 = numpy.power(A-B, 2).sum()
>>> d2
27
>>> d2 = numpy.power(A-B, 2)
>>> d2
array([9, 9, 9])
>>>