import tensorflow as tf

g1 = tf.Graph()
with g1.as_default():
    v = tf.get_variable(
        "v", initializer=tf.zeros_initializer()(shape=[1])
    )

g2 = tf.Graph()
with g2.as_default():
    v = tf.get_variable(
        "v", initializer=tf.ones_initializer()(shape=[1])
    )

with tf.Session(graph=g1) as sess:
    tf.global_variables_initializer().run()
    with tf.variable_scope("", reuse=True):
        print(sess.run(tf.get_variable("v")))

with tf.Session(graph=g2) as sess:
    tf.global_variables_initializer().run()
    with tf.variable_scope("", reuse=True):
        print(sess.run(tf.get_variable("v")))

# gpu acceleration
a = tf.constant([1.0, 3.0], name="a")
b = tf.constant([3.0, 6.0], name="b")
g = tf.Graph()
with g.device('/gpu:0'):
    result = a+b
    sess = tf.Session()
    print (sess.run(result))