class my_NN(object):
    def __init__(self):
        self.input = 4 # feature numbers
        self.output = 1 # class number
        self.hidden_units = 6 # single layer

        # initialize matrix of weights;
        np.random.seed(1)
        # weight1: input -> hidden layer
        self.w1 = np.random.randn(self.input, self.hidden_units) # 4*6 matrix
        # weight2: hidden layer -> output
        self.w2 = np.random.randn(self.hidden_units, self.output) # 6*1 matrix