115、TensorFlow变量的使用

# To use the value of a tf.Variable in a Tesnorflow graph , simply treat it like a normal tf.Tensor
import  tensorflow as tf
v = tf.get_variable("v", shape=(), initializer=tf.zeros_initializer())
w = v + 1  # w is a tf.Tensor which is computed based on the value of v
# Any time a variable is used in an expression it gets automatically
# converted to a tf.Tensor representing its value
# To assign a value to a variable , use the methods assign , assign_add
# and friends in the tf.Variable class . For example 
v1 = tf.get_variable("v1", shape=(), initializer=tf.zeros_initializer())
assignment = v1.assign_add(1)
with tf.Session() as sess:
    tf.global_variables_initializer().run()
    print(sess.run(assignment))

下面是输出的结果

2018-02-17 10:55:36.215165: I C:	f_jenkinsworkspace
el-winMwindowsPY35	ensorflowcoreplatformcpu_feature_guard.cc:137] Your CPU supports instructions that this TensorFlow binary was not compiled to use: AVX AVX2
1.0