tensorflow--Hello World

tensorflow内部原理可参考tensorflow原理

import tensorflow as tf

# Simple hello world using TensorFlow

# Create a Constant op
# The op is added as a node to the default graph.
#
# The value returned by the constructor represents the output
# of the Constant op.
hello = tf.constant('Hello, TensorFlow!')

# Start tf session
sess = tf.Session()

# Run the op
print(sess.run(hello))

sess.close()

tf.constant(
    value, #可以是常数或list
    dtype=None,
    shape=None, #若定义了该属性，list维度不足，则以最后list的最后一个元素补全
    name='Const',
    verify_shape=False
)#创建一个常数张量

sess = tf.Session() #Session为所有操作和张量提供了资源，不使用时必须释放sess.close()

run(
    fetches, #can be single graph element, list, tuple, namedtuple, dict etc
    feed_dict=None,
    options=None,
    run_metadata=None
) #执行所有计算和张量赋值