import numpy as np

class Network(object):

    def __init__(self,sizes):
        self.num_layers = len(sizes)
        self.sizes = sizes
        self.biases = [np.random.randn(y,1) for y in sizes[1:]]
        self.weights = [np.random.randn(y,x)
                        for x,y in zip(sizes[:-1],sizes[1:])]

net = Network([2,3,1])
print(net.sizes)
print(net.biases)
print(net.weights)
