Tensorflow Practice 2-2

import tensorflow as tf
import os
os.environ['TF_CPP_MIN_LOG_LEVEL'] = '2'

x = tf.Variable([1, 2])
a = tf.constant([3, 3])
'''增加一个减法op'''
sub = tf.subtract(x, a)
'''增加一个加法op'''
add = tf.add(x, sub)

init = tf.global_variables_initializer()

with tf.Session() as sess:
    sess.run(init)
    print(sess.run(sub))
    print(sess.run(add))

'''创建一个变量初始化为0'''
state = tf.Variable(0, name='counter')
'''创建一个op，作用是使state加1'''
new_value = tf.add(state, 1)
'''赋值op'''
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))