import tensorflow as tf

X = tf.placeholder(tf.float32, [None, 3])
print(X)

x_data = [[1,2,3], [4,5,6]]

W = tf.Variable(tf.random_normal([3, 2]))
b = tf.Variable(tf.random_normal([2, 1]))

expr = tf.matmul(X, W) + b

sess = tf.Session()
sess.run(tf.global_variables_initializer())

print(x_data)
print(sess.run(W))
print(sess.run(b))

print("=== expr ===")
print(sess.run(expr, feed_dict={X: x_data}))

sess.close()