fetch and feed 用法演示：
#-*-coding:utf-8-*-
import tensorflow as tf
#fetch 的用法：
input1 = tf.constant(2.0)
input2 = tf.constant(3.0)
input3 = tf.constant(5.0)
add = tf.add(input2,input3)
mul = tf.multiply(add,input1)
with tf.Session() as sess:#fetch 就是能够同时run 两个op运算result = sess.run([mul,add])print(result)#feed 的用法：
#使用占位符
input1 = tf.placeholder(tf.float32)
input2 = tf.placeholder(tf.float32)
output = tf.multiply(input1,input2)
with tf.Session() as sess:#feed 的用法就是在run 的时候对占位符用字典的形式赋值result = sess.run(output,feed_dict={input1:[8.],input2:[7.]})print(result)运行结果：
