利用tensorflow实现前向传播

import tensorflow as tf

w1 = tf.Variable(tf.random_normal((2, 3), stddev=1, seed=1))
w2 = tf.Variable(tf.random_normal((3, 1), stddev=1, seed=1))

x = tf.constant([[0.7, 0.9]])

a = tf.matmul(x, w1)
y = tf.matmul(a, w2)

init_op = tf.global_variables_initializer()

with tf.Session() as sess:
    sess.run(init_op)
    print(sess.run(y))