Human Class with bmi as per step 6

class Human(object):

      def __init__(self,*args,**kwargs):
          self.first_name=kwargs.setdefault('first')
          self.last_name=kwargs.setdefault('last')
          self.height = kwargs.setdefault('height')
          self.weight = kwargs.setdefault('weight')
      def bmi(self):
          return self.weight/float(self.height)**2

Human.bmi = bmi