import tensorflow as tf

# Fetch:可以在session中同时计算多个tensor或执行多个操作

# 定义三个常量

input1 = tf.constant(3.0)

input2 = tf.constant(2.0)

input3 = tf.constant(5.0)

# 加法op

add = tf.add(input2,input3)

# 乘法op

mul = tf.multiply(input1, add)

with tf.Session() as sess:

    result1,result2 = sess.run([mul, add])

    print(result1,result2)

# Feed:先定义占位符，等需要的时候再传入数据

input1 = tf.placeholder(tf.float32)

input2 = tf.placeholder(tf.float32)

# 乘法op

output = tf.multiply(input1, input2)

with tf.Session() as sess:

    print(sess.run(output, feed_dict={input1:8.0,input2:2.0}))