tensorflow基础 fetch feed

import tensorflow as tf
c1 = tf.constant([[3,3]])
c2  = tf.constant([[3],[2]])
product = tf.matmul(c1 , c2)
with tf.Session() as sess:
    reslut = sess.run(product)
    print(reslut)

state = tf.Variable(0,name='counter')

#add
new_value = tf.add(state,1)

#update
# update = tf.assign(new_value , state)
update = tf.assign(state , new_value)
init = tf.global_variables_initializer()

with tf.Session() as sess:
    sess.run(init)
    print(sess.run(state))
    for _ in range(5):
        print(sess.run(update))
    print(sess.run(state))

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#===============================
import tensorflow as tf
#fetch

c1 = tf.constant([3])
c2 = tf.constant([1])
c3 = tf.constant([6])

#add
add = tf.add(c1,c2)
mul = tf.multiply(c3,add)

with tf.Session() as sess:
    print(sess.run([add,mul]))


21.0  7.0
#======================
#feed
c1 = tf.placeholder(tf.float32)
c2 = tf.placeholder(tf.float32)

add = tf.add(c1,c2)

with tf.Session() as sess:
    print(sess.run(add,feed_dict={c1:[2],c2:[22]}))

#24.0